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1

X-ray optics for emission line X-ray source diffraction enhanced systems  

Microsoft Academic Search

Diffraction-enhanced X-ray imaging (DEI) is one of a class of imaging techniques developed at a synchrotron that is based on contrast mechanisms other than absorption. This method uses perfect crystal optics to prepare and analyze beams that traverse the object imaged. The combination of a highly collimated beam along with an analyzer gives such system sensitivity to X-ray refraction and

D. Chapman; I. Nesch; M. O. Hasnah; T. I. Morrison

2006-01-01

2

EFFECT OF SATELLITE LINES FROM X-RAY SOURCE ON X-RAY DIFFRACTION PEAKS  

EPA Science Inventory

The article discusses the development of a method for relating reactivity to crystallite size and strain parameters obtained by the Warren-Averbach technique. PA has been using crystallite size and strain data obtained from x-ray diffraction (XRD) peak profile analysis to predict...

3

X-RAY DIFFRACTION LINE PROFILES OF ELECTROGRAPHITIZED CARBON PRODUCTS  

Microsoft Academic Search

The (001) diffraction line profiles of electrographitized carbon ; products were graphically separated into profiles of their component carbons. ; The products used for this experiment were made from a petroleum coke, a thermal ; black, or a furnace black and a binder pitch. The ratios of the integrated ; difiraction intensities of the component carbons were in good agreement

T. Noda; M. Inagaki; C. Sugie

1961-01-01

4

X-Ray Diffraction  

NSDL National Science Digital Library

This site from the University of London presents a tutorial on several methods of X-ray diffraction, including the powder, rotating crystal, and Laue methods Each section includes interactive Java applets, exercises, and links to a glossary of terms.

Matter.org

5

Microhardness evaluation of Cu–Ni multilayered films by X-ray diffraction line profile analysis  

Microsoft Academic Search

Copper–nickel multilayered films were sputtered on silicon and stainless steel substrates, respectively. The dislocation density and the dislocation distribution parameter in multilayered films were deduced with X-ray diffraction line profile analysis method. Microhardness was calculated from the dislocation data. The results show that the microhardness values are in a good agreement between calculated values and measured values.

F. L Shan; Z. M Gao; Y. M Wang

1998-01-01

6

Preliminary on-Line Analysis, by X-Ray Diffraction, of Pyrite-Containing Slurries.  

National Technical Information Service (NTIS)

An on-line instrument, which was developed by the National Institute for Metallurgy, was used in a feasibility study on the applicability of X-ray diffraction to the analysis of the pyrite content of flotation concentrates from the gold-mining industry. T...

J. P. R. De Villiers

1981-01-01

7

X-ray Diffraction  

NSDL National Science Digital Library

A series of laboratory activities on x-ray diffraction physics using the Teltron Tel-X-Ometer System. Detailed explanations on the production and delivery of the beam is included, as well as a very complete safety protocol for conducting the experiments.

Langan, Shawn

2012-03-08

8

Grain orientation mapping of passivated aluminum interconnect lines by x-ray micro-diffraction  

SciTech Connect

A micro x-ray diffraction facility is under development at the Advanced Light Source. Spot sizes are typically about 1-{mu}m size generated by means of grazing incidence Kirkpatrick-Baez focusing mirrors. Photon energy is either white of energy range 6-14 keV or monochromatic generated from a pair of channel cut crystals. Laue diffraction pattern from a single grain in a passivated 2-{mu}m wide bamboo structured Aluminum interconnect line has been recorded. Acquisition times are of the order of seconds. The Laue pattern has allowed the determination of the crystallographic orientation of individual grains along the line length. The experimental and analysis procedure used is described, as is the latest grain orientation result. The impact of x-ray micro-diffraction and its possible future direction are discussed in the context of other developments in the area of electromigration, and other technological problems.

Chang, C. H.; Patel, J. R. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); SSRL/SLAC, Stanford University, Stanford, California 94309 (United States); MacDowell, A. A.; Padmore, H. A. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Thompson, A. C. [Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

1998-11-24

9

Grain orientation mapping of passivated aluminum interconnect lines with X-ray micro-diffraction  

SciTech Connect

A micro x-ray diffraction facility is under development at the Advanced Light Source. Spot sizes are typically about 1-{micro}m size generated by means of grazing incidence Kirkpatrick-Baez focusing mirrors. Photon energy is either white of energy range 6--14 keV or monochromatic generated from a pair of channel cut crystals. Laue diffraction pattern from a single grain in a passivated 2-{micro}m wide bamboo structured Aluminum interconnect line has been recorded. Acquisition times are of the order of seconds. The Laue pattern has allowed the determination of the crystallographic orientation of individual grains along the line length. The experimental and analysis procedure used is described, as is the latest grain orientation result. The impact of x-ray micro-diffraction and its possible future direction are discussed in the context of other developments in the area of electromigration, and other technological problems.

Chang, C.H.; Patel, J.R. [Lawrence Berkeley National Lab., CA (United States). Advanced Light Source Div.]|[Stanford Univ., CA (United States); MacDowell, A.A.; Padmore, H.A.; Thompson, A.C. [Lawrence Berkeley National Lab., CA (United States)

1998-09-01

10

Grain orientation mapping of passivated aluminum interconnect lines by x-ray micro-diffraction  

SciTech Connect

A micro x-ray diffraction facility is under development at the Advanced Light Source. Spot sizes are typically about 1-{mu}m size generated by means of grazing incidence Kirkpatrick-Baez focusing mirrors. Photon energy is either white of energy range 6{endash}14 keV or monochromatic generated from a pair of channel cut crystals. Laue diffraction pattern from a single grain in a passivated 2-{mu}m wide bamboo structured Aluminum interconnect line has been recorded. Acquisition times are of the order of seconds. The Laue pattern has allowed the determination of the crystallographic orientation of individual grains along the line length. The experimental and analysis procedure used is described, as is the latest grain orientation result. The impact of x-ray micro-diffraction and its possible future direction are discussed in the context of other developments in the area of electromigration, and other technological problems. {copyright} {ital 1998 American Institute of Physics.}

Chang, C.H.; MacDowell, A.A.; Padmore, H.A.; Patel, J.R. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Patel, J.R. [SSRL/SLAC, Stanford University, Stanford, California 94309 (United States)] Thompson, A.C. [Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

1998-11-01

11

THE EFFECT OF SATELLITE LINES FROM THE X-RAY SOURCE ON X-RAY DIFFRACTION PEAKS  

EPA Science Inventory

The article discusses the development of a method for relating reactivity to crystallite size and strain parameters obtained by the Warren-Averbach technique. EPA has been using crystallite size and strain data obtained from x-ray diffraction (XRD) peak profile analysis to predic...

12

Determination of dislocation densities in HCP metals from X-ray diffraction line-broadening analysis  

Microsoft Academic Search

X-Ray diffraction (XRD) line-broadening analysis has been performed on highly textured Zr-2.5Nb specimens which had been deformed\\u000a in tensile tests to produce well-controlled dislocation structures. An iterative deconvolution method has been applied to\\u000a extract the broadening function for the material, using as standards, a Zr single crystal and a 0 pct deformed specimen. In\\u000a both cases, for specific tensile tests,

M. Griffiths; D. Sage; R. A. Holt; C. N. Tome

2002-01-01

13

Design and performance of a focused beam line for surface x-ray diffraction  

Microsoft Academic Search

Focusing optics have been installed on the 5.0 T Wiggler beam line of the SRS at Daresbury Laboratory for use with x-ray diffraction measurements of surfaces and interfaces. A significant increase in the flux has been achieved without excessive degradation of the resolution in the vertical plane. The full width at half-maximum of the focused image compares well with the

C. Norris; M. S. Finney; G. F. Clark; G. Baker; P. R. Moore; R. van Silfhout

1992-01-01

14

A Novel X-ray Diffraction and Reflectivity Tool for Front-End of Line Metrology  

NASA Astrophysics Data System (ADS)

High-resolution X-ray diffraction (HRXRD) is an established technique for the characterization and metrology of epitaxial thin-films. However, its use by the silicon semiconductor industry has been limited due to the stringent reliability, spot-size and throughput requirements for in-line measurement of product wafers. We have developed a new X-ray metrology tool (called the JVX 7200) that meets these demands. The tool features a novel HRXRD channel that provides composition, relaxation and thickness information for SiGe and Si:C epitaxial films. It also combines an enhanced X-ray reflectivity (XRR) channel to provide complementary thickness, density and roughness information on SiGe as well as other front-end of line (FEOL) films, such as those found in high-k gate/metal gate (HKMG) stacks. We describe the principles and capabilities of both the HRXRD and XRR channels and provide a comparison with conventional X-ray systems. Representative data are presented to highlight the capabilities of the new tool.

Wormington, M.; Yokhin, B.; Berman, D.; Krokhmal, A.; Mazor, I.; Ryan, P.; Wall, J.; Bytheway, R.

2011-11-01

15

Observation of semiconductor device channel strain using in-line high resolution X-ray diffraction  

NASA Astrophysics Data System (ADS)

In-line high resolution X-ray diffraction has been used to analyze embedded silicon-germanium (eSiGe) epitaxially grown in the source/drain regions of complementary metal-oxide-semiconductor devices. Compared to blanket films, the diffraction from patterned devices exhibited distinct features corresponding to the eSiGe in the source/drain regions and Si under the gate and SiGe. The diffraction features modulated with structural changes, alloy composition, and subsequent thermal processing. Reciprocal space measurements taken around the (224) diffraction peak revealed both in-plane (h) and out-of-plane (l) lattice deformation, along with features corresponding to the regular spacing between the gates.

Holt, Judson R.; Madan, Anita; Harley, Eric C. T.; Stoker, Matt W.; Pinto, Teresa; Schepis, Dominic J.; Adam, Thomas N.; Murray, Conal E.; Bedell, Stephen W.; Holt, Martin

2013-10-01

16

Focusing and Imaging Sharp Line X-Ray and gamma-Ray Sources Using Variable-Metric Diffraction Crystals.  

National Technical Information Service (NTIS)

A new method has been devised for focusing and imaging the radiation from sharp-line sources of x-rays and gamma-rays, which makes use of variable-metric diffraction crystals. A variable-metric diffraction crystal is one in which the spacings between the ...

R. K. Smither

1982-01-01

17

Deformation characteristics of rolled zirconium alloys: a study by X-ray diffraction line profile analysis  

SciTech Connect

Different techniques of the X-ray diffraction line profile analysis (XRDLPA) have been used to study the microstructural parameters of the heavily deformed solid polycrystalline Zircaloy-2 and Zr-2.5%Nb alloys. The domain size, microstrain within the domain, dislocation density and the stacking fault probabilities have been estimated by the Simplified Breadth Method, Williamson-Hall technique and the Modified Rietveld Method. A clear signature of the anisotropy in the domain shape was revealed. The domain size (D{sub e}) was quantified along the different crystallographic directions. In these deformed alloys, the dislocation density ({rho}{sub e}) was of the order of 10{sup 15} m{sup -2} but the stacking fault probabilities were almost negligible. For the first time, we could establish an empirical relationship between D{sub e} and ({rho}e)-12 for these hexagonal closed packed alloys.

Mukherjee, P. [Variable Energy Cyclotron Centre, Department of Atomic Energy, Block 1/AF Bidhannagar, Kolkata 700064 (India)]. E-mail: paramita@veccal.ernet.in; Sarkar, A. [Variable Energy Cyclotron Centre, Department of Atomic Energy, Block 1/AF Bidhannagar, Kolkata 700064 (India); Barat, P. [Variable Energy Cyclotron Centre, Department of Atomic Energy, Block 1/AF Bidhannagar, Kolkata 700064 (India); Bandyopadhyay, S.K. [Variable Energy Cyclotron Centre, Department of Atomic Energy, Block 1/AF Bidhannagar, Kolkata 700064 (India); Sen, Pintu [Variable Energy Cyclotron Centre, Department of Atomic Energy, Block 1/AF Bidhannagar, Kolkata 700064 (India); Chattopadhyay, S.K. [Regional Engineering College, Durgapur 713209 (India); Chatterjee, P. [Department of Physics, Vivekananda Mahavidyalaya, Haripal, Hooghly 712405 (India); Chatterjee, S.K. [Regional Engineering College, Durgapur 713209 (India); Mitra, M.K. [Faculty of Engineering and Technology, Jadavpur University, Kolkata 700032 (India)

2004-11-08

18

Submicron X-ray diffraction  

SciTech Connect

At the Advanced Light Source in Berkeley the authors have instrumented a beam line that is devoted exclusively to x-ray micro diffraction problems. By micro diffraction they mean those classes of problems in Physics and Materials Science that require x-ray beam sizes in the sub-micron range. The instrument is for instance, capable of probing a sub-micron size volume inside micron sized aluminum metal grains buried under a silicon dioxide insulating layer. The resulting Laue pattern is collected on a large area CCD detector and automatically indexed to yield the grain orientation and deviatoric (distortional) strain tensor of this sub-micron volume. A four-crystal monochromator is then inserted into the beam, which allows monochromatic light to illuminate the same part of the sample. Measurement of diffracted photon energy allows for the determination of d spacings. The combination of white and monochromatic beam measurements allow for the determination of the total strain/stress tensor (6 components) inside each sub-micron sized illuminated volume of the sample.

MacDowell, Alastair; Celestre, Richard; Tamura, Nobumichi; Spolenak, Ralph; Valek, Bryan; Brown, Walter; Bravman, John; Padmore, Howard; Batterman, Boris; Patel, Jamshed

2000-08-17

19

Stacking Fault Energies of fcc Fe-Ni Alloys by X-Ray Diffraction Line Profile Analysis.  

National Technical Information Service (NTIS)

The stacking fault energies of the fcc alloy series Fe-28 Ni to pure Ni were investigated using x-ray diffraction line profile analysis. A minimum stacking fault energy of about 70 mJ/sq m occurs at the approximate composition of Fe 40Ni. From this point,...

R. E. Schramm R. P. Reed

1975-01-01

20

THE CHARACTERIZATION OF A SOLID SORBENT WITH CRYSTALLITE SIZE AND STRAIN DATA FROM X-RAY DIFFRACTION LINE BROADENING  

EPA Science Inventory

The paper gives results of the characterization of a solid sorbent with crystallite size and strain data from x-ray diffraction line broadening, as part of an EPA investigation of the injection of dry Ca(OH)2 into coal-fired electric power plant burners for the control of SO2 emi...

21

Line x-ray source for diffraction enhanced imaging in clinical and industrial applications  

Microsoft Academic Search

Mammography is one type of imaging modalities that uses a low-dose x-ray or other radiation sources for examination of breasts. It plays a central role in early detection of breast cancers. The material similarity of tumor-cell and health cell, breast implants surgery and other factors, make the breast cancers hard to visualize and detect. Diffraction enhanced imaging (DEI), first proposed

Xiaoqin Wang

2006-01-01

22

The features of identifying lines in a diffraction image formed by a widely divergent X-ray beam  

SciTech Connect

A method for identifying lines in a diffraction image formed by a widely divergent X-ray beam and a technique for measuring the crystal structure parameters in the case of asymmetric crystal position have been developed. It is established that, once the distances between a crystal and a photographic plate and between the points of intersection of the hyperbola branches in a diffraction image are known, one can determine the angle between the crystal's zone axis and the wave vector, which leads to multiwave diffraction. Relations linking this angle with the parameters of two atomic planes are obtained. It is found that, to measure the parameters of atomic planes belonging to a given zone, one can use different sets of crossed hyperbolas formed by radiations K{sub {alpha}} and K{sub {beta}}. The measurements and calculations performed for the same sample (Si crystal), mounted symmetrically and asymmetrically, confirm the reliability of the proposed method.

Avetyan, K. T., E-mail: nazaryan.ernest@netsys.am; Levonyan, L. V.; Arakelyan, M. M., E-mail: marakelyan@ysu.am; Semerjian, H. S.; Grigoryan, P. A.; Hovhannisyan, G. M. [Yerevan State University (Armenia)

2009-05-15

23

In-Line Monitoring of Fab Processing Using X-Ray Diffraction  

NASA Astrophysics Data System (ADS)

As the materials shift that started with Cu continues to advance in the semiconductor industry, new issues related to materials microstructure have arisen. While x-ray diffraction (XRD) has long been used in development applications, in this paper we show that results generated in real time by a unique, high throughput, fully automated XRD metrology tool can be used to develop metrics for qualification and monitoring of critical processes in current and future manufacturing. It will be shown that these metrics provide a unique set of data that correlate to manufacturing issues. For example, ionized-sputtering is the current deposition method of choice for both the Cu seed and TaNx/Ta barrier layers. The alpha phase of Ta is widely used in production for the upper layer of the barrier stack, but complete elimination of the beta phase requires a TaNx layer with sufficient N content, but not so much as to start poisoning the target and generating particle issues. This is a well documented issue, but traditional monitoring by sheet resistance methods cannot guarantee the absence of the beta phase, whereas XRD can determine the presence of even small amounts of beta. Nickel silicide for gate metallization is another example where monitoring of phase is critical. As well being able to qualify an anneal process that gives only the desired NiSi phase everywhere across the wafer, XRD can be used to determine if full silicidation of the Ni has occurred and characterize the crystallographic microstructure of the Ni to determine any effect of that microstructure on the anneal process. The post-anneal nickel silicide phase and uniformity of the silicide microstructure can all be monitored in production. Other examples of the application of XRD to process qualification and production monitoring are derived from the dependence of certain processes, some types of defect generation, and device performance on crystallographic texture. The data presented will show that CMP dishing problems could be traced to texture of the barrier layer and mitigated by adjusting the barrier process. The density of pits developed during CMP of electrochemically deposited (ECD) Cu depends on the fraction of (111) oriented grains. It must be emphasized that the crystallographic texture is not only a key parameter for qualification of high yielding and reliable processes, but also serves as a critical parameter for monitoring tool health. The texture of Cu and W are sensitive not only to deviations in performance of the tool depositing or annealing a particular film, but also highly sensitive to the texture of the barrier underlayers and thus any performance deviations in those tools. The XRD metrology tool has been designed with production monitoring in mind and has been fully integrated into both 200 mm and 300 mm fabs. Rapid analysis is achieved by using a high intensity fixed x-ray source, coupled with a large area 2D detector. The output metrics from one point are generated while the tool is measuring a subsequent point, giving true on-the-fly analysis; no post-processing of data is necessary. Spatial resolution on the wafer surface ranging from 35 ?m to 1 mm is available, making the tool suitable for monitoring of product wafers. Typical analysis times range from 10 seconds to 2 minutes per point, depending on the film thickness and spot size. Current metrics used for process qualification and production monitoring are phase, FWHM of the primary phase peaks (for mean grain size tracking), and crystallographic texture.

Gittleman, Bruce; Kozaczek, Kris

2005-09-01

24

{ital In} {ital situ} x-ray diffraction analysis of the C49--C54 titanium silicide phase transformation in narrow lines  

SciTech Connect

The transformation of titanium silicide from the C49 to the C54 structure was studied using x-ray diffraction of samples containing arrays of narrow lines of preformed C49 TiSi{sub 2}. Using a synchrotron x-ray source, diffraction patterns were collected at 1.5--2 {degree}C intervals during sample heating at rates of 3 or 20 {degree}C/s to temperatures of 1000--1100 {degree}C. The results show a monotonic increase in the C54 transition temperature by as much as 180 {degree}C with a decreasing linewidth from 1.0 to 0.1 {mu}m. Also observed is a monotonic increase in (040) preferred orientation of the C54 phase with decreasing linewidth. The results demonstrate the power of {ital in} {ital situ} x-ray diffraction of narrow line arrays as a tool to study finite size effects in thin-film reactions.

Roy, R.A.; Clevenger, L.A.; Cabral, C. Jr.; Saenger, K.L.; Brauer, S.; Jordan-Sweet, J.; Bucchignano, J.; Stephenson, G.B. [IBM Research Division, T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Morales, G.; Ludwig, K.F. Jr. [Department of Physics, Boston University, Boston, Massachusetts 02215 (United States)

1995-04-03

25

The multipurpose X-ray diffraction end-station of the BM25B-SpLine synchrotron beamline at the ESRF  

NASA Astrophysics Data System (ADS)

The Spanish BM25-SpLine beamline at the European Synchrotron Radiation Facility allocates in the first focal point of Branch B a versatile experimental set-up devoted to X-ray diffraction studies. X-Ray Reflectivity, Reciprocal Space Maps, Surface, Single Crystal, Grazing Incidence and High Resolution Powder Diffraction can be performed using a point detector or a 2D detector (Charge-Coupled Device), in combination with many sample environment setups. A detailed description of the end-station is presented, including several examples that demonstrate the excellent capabilities of the setup.

Rubio-Zuazo, J.; Ferrer, P.; López, A.; Gutiérrez-León, A.; da Silva, I.; Castro, G. R.

2013-07-01

26

Polymorphic transformation of L-glutamic acid monitored using combined on-line video microscopy and X-ray diffraction  

NASA Astrophysics Data System (ADS)

Enhancement of process monitoring for detecting transformations of the organic solid state is an important, strategic area currently of substantial interest particularly to the pharmaceutical sector and, more generally, manufacturers of speciality chemical products. A feasibility study is reported in which a solution-mediated polymorphic transformation of L-glutamic acid (LGA) was monitored using, concurrently, both video microscopy accompanied by advanced image processing and, on-line X-ray diffraction. The applicability of these monitoring approaches, applied individually, has been demonstrated previously; however, it was useful to assess the relative sensitivity of the two techniques by their direct comparison, via simultaneous use, during application on-line to monitor a polymorphic transformation process. It was found that the onset of the polymorphic transformation, manifested as the point in time when crystals of the ? phase of LGA were first detected, was elucidated as being significantly sooner via video microscopy. This reflects the fact that the concentration regimes of maximum sensitivity for the individual approaches are complementary, hence video microscopy provides considerable added-value allowing detection of the early stages of the transformation process. Currently, the upper bound on solids concentration that is compatible with extracting useful information about the phase composition using video microscopy, based on particle shape, is restricted. However, it is anticipated that improvements to both the experimental design and the image processing algorithms applied will substantially increase this upper bound allowing practical application under realistic processing conditions.

Dharmayat, Spoorthi; Calderon de Anda, Jorge; Hammond, Robert B.; Lai, Xaiojun; Roberts, Kevin J.; Wang, Xue Z.

2006-08-01

27

The X-ray diffraction grating  

Microsoft Academic Search

Grazing incidence diffraction performance and imagery are discussed, with special reference to corrected systems. Throughout the period 1930-1970 the principal aim of X-ray grating research centered on the problem of the optimum groove profile and its practical realization. This was due to the fact that, unlike their optical or UV counterparts, X-ray gratings rarely diffracted more than a percent or

R. J. Speer

1976-01-01

28

X-ray Diffraction Gratings for Astrophysics  

NASA Astrophysics Data System (ADS)

Over the past year, we have celebrated the tenth anniversary of the Chandra and XMM-Newton X-ray observatories. Both carry powerful, novel diffraction grating spectrometers, which have opened true X-ray spectroscopy for astrophysics. I will describe the design and operation of these instruments, as the background to some of the beautiful results they have produced. But these designs do not exhaust the versatility and essential simplicity of diffraction grating spectrometers, and I will discuss applications for the International X-ray Observatory IXO.

Paerels, Frits

2010-12-01

29

An Analysis of X-Ray Diffraction Line Profiles of Microcrystalline Muscovites  

Microsoft Academic Search

Previous studies of the line profiles of the basal reflections of microcrystalline muscovites were refined by an adaptation of the method developed by Maire and Mrring. In order to evaluate the variation of interlayer spacings, the method required only relative values of Fourier coefficients, without the correction for instrumental broadening, which was the source of one of the moist critical

H. KODAMAt; L. GATINEAU; J. MitRING

1971-01-01

30

Focusing and imaging sharp line x-ray and gamma-ray sources using variable-metric diffraction crystals. [Gamma ray telescopes  

Microsoft Academic Search

A new method has been devised for focusing and imaging the radiation from sharp-line sources of x-rays and gamma-rays, which makes use of variable-metric diffraction crystals. A variable-metric diffraction crystal is one in which the spacings between the crystalline planes is varied as a function of position in the crystal by either the application of a thermal gradient or by

Smither

1982-01-01

31

Application of synchrotron radiation in X-ray diffraction studies of crystal structures  

Microsoft Academic Search

The use of synchrotron radiation in studies of crystal structures by X-ray diffraction is reviewed. The beam lines and detectors used for diffraction experiments are described and the special characteristics of synchrotron X-ray radiation discussed

Zbigniew Dauter

1996-01-01

32

Diffraction enhanced x-ray imaging  

SciTech Connect

Diffraction enhanced imaging (DEI) is a new x-ray radiographic imaging modality using synchrotron x-rays which produces images of thick absorbing objects that are almost completely free of scatter. They show dramatically improved contrast over standard imaging applied to the same phantoms. The contrast is based not only on attenuation but also the refraction and diffraction properties of the sample. The diffraction component and the apparent absorption component (absorption plus extinction contrast) can each be determined independently. This imaging method may improve the image quality for medical applications such as mammography.

Thomlinson, W.; Zhong, Z. [Brookhaven National Lab., Upton, NY (United States). National Synchrotron Light Source; Chapman, D. [Illinois Inst. of Tech., Chicago, IL (United States); Johnston, R.E. [Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Radiology; Sayers, D. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Physics

1997-09-01

33

X-ray dynamical diffraction Fraunhofer holography.  

PubMed

An X-ray dynamical diffraction Fraunhofer holographic scheme is proposed. Theoretically it is shown that the reconstruction of the object image by visible light is possible. The spatial and temporal coherence requirements of the incident X-ray beam are considered. As an example, the hologram recording as well as the reconstruction by visible light of an absolutely absorbing wire are discussed. PMID:23955039

Balyan, Minas

2013-08-06

34

Single Particle X-ray Diffractive Imaging  

SciTech Connect

In nanotechnology, strategies for the creation and manipulation of nanoparticles in the gas phase are critically important for surface modification and substrate-free characterization. Recent coherent diffractive imaging with intense femtosecond X-ray pulses has verified the capability of single-shot imaging of nanoscale objects at sub-optical resolutions beyond the radiation-induced damage threshold. By intercepting electrospray-generated particles with a single 15 femtosecond soft-X-ray pulse, we demonstrate diffractive imaging of a nanoscale specimen in free flight for the first time, an important step toward imaging uncrystallized biomolecules.

Bogan, M J; Benner, W H; Boutet, S; Rohner, U; Frank, M; Seibert, M; Maia, F; Barty, A; Bajt, S; Riot, V; Woods, B; Marchesini, S; Hau-Riege, S P; Svenda, M; Marklund, E; Spiller, E; Hajdu, J; Chapman, H N

2007-10-01

35

Microstructural studies on lattice imperfections in irradiated titanium and Ti5 Pct Ta2 Pct Nb by X-ray diffraction line-profile analysis  

Microsoft Academic Search

Microstructural parameters such as the average domain size, effective domain size at a particular crystallographic direction,\\u000a and microstrain within the domains of titanium and Ti-5 pct Ta-2 pct Nb, irradiated with 116 MeV O5+ ion, have been characterized as a function of dose by X-ray diffraction line-profile analysis (XRDLPA) using different model-based\\u000a approaches. The dislocation density and stacking-fault probabilities have

P. Mukherjee; F. A. Sarkar; P. Barat; Baldev Raj; U. Kamachi Mudali

2005-01-01

36

Microstructural studies on lattice imperfections in irradiated Titanium and Ti5%Ta2%Nb by X-Ray Diffraction Line Profile Analysis  

Microsoft Academic Search

The microstructural parameters like the average domain size, effective domain size at a particular crystallographic direction and microstrain within the domains of titanium and Ti-5%Ta-2%Nb, irradiated with 116 MeV O5+ ion, have been characterized as a function of dose by X-Ray Diffraction Line Profile Analysis using different model based approaches. Dislocation Density and stacking fault probabilities have also been estimated

P. Mukherjee; A. Sarkar; P. Barat; Baldev Raj; U. Kamachi Mudali

2005-01-01

37

X-Ray Diffraction on Radioactive Materials.  

National Technical Information Service (NTIS)

X-ray diffraction studies on radioactive materials are discussed with the aim of providing a guide to new researchers in the field. Considerable emphasis is placed on the safe handling and loading of not-too-exotic samples. Special considerations such as ...

D. Schiferl R. B. Roof

1978-01-01

38

The Dynamical Theory of X Ray Diffraction  

ERIC Educational Resources Information Center

Summarizes the Darwin theory of x-ray diffraction in thin crystals or crystals with a mosaic texture and its modified application to crystals with three-dimensional electrostatic dipoles. Indicates that the dynamical theory is brought into its present relevance by the improvement of single crystal growth techniques. (CC)

Balchin, A. A.; Whitehouse, C. R.

1974-01-01

39

Standard X-Ray Diffraction Powder Patterns.  

National Technical Information Service (NTIS)

Standard x-ray diffraction powder patterns are presented for the following fifty-one substances: 3A12O3.2SiO2, (mullite); (NH4)2BeF4; NH4BF4; Sb2Se3*; Sb2Te3*; As2O3*, claudetite; BaBr2.H2O*; BaSnO3; BiPO4 (monoclinic); Bi2Te3, (tellurobismuthite); Bi2O3,...

H. E. Swanson M. C. Morris E. H. Evans L. Ulmer

1964-01-01

40

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

2012-02-15

41

Structural investigations of epitaxial InN by x-ray photoelectron diffraction and x-ray diffraction  

Microsoft Academic Search

The authors investigated a 1 mum thick molecular beam epitaxy-grown InN film by means of full hemispherical x-ray photoelectron diffraction and high resolution x-ray diffraction. While x-ray diffraction reveals that this nominally hexagonal InN layer contains roughly 1% of cubic phase InN, a comparison between measured and simulated x-ray photoelectron diffraction data allowed them to directly determine the polarity of

Daniel Hofstetter; Laurent Despont; M. Gunnar Garnier; Esther Baumann; Fabrizio R. Giorgetta; Philipp Aebi; Lutz Kirste; Hai Lu; William J. Schaff

2007-01-01

42

Optical properties of X-rays--dynamical diffraction.  

PubMed

The first attempts at measuring the optical properties of X-rays such as refraction, reflection and diffraction are described. The main ideas forming the basis of Ewald's thesis in 1912 are then summarized. The first extension of Ewald's thesis to the X-ray case is the introduction of the reciprocal lattice. In the next step, the principles of the three versions of the dynamical theory of diffraction, by Darwin, Ewald and Laue, are given. It is shown how the comparison of the dynamical and geometrical theories of diffraction led Darwin to propose his extinction theory. The main optical properties of X-ray wavefields at the Bragg incidence are then reviewed: Pendellösung, shift of the Bragg peak, fine structure of Kossel lines, standing waves, anomalous absorption, paths of wavefields inside the crystal, Borrmann fan and double refraction. Lastly, some of the modern applications of the dynamical theory are briefly outlined: X-ray topography, location of adsorbed atoms at crystal surfaces, optical devices for synchrotron radiation and X-ray interferometry. PMID:22186282

Authier, André

2011-12-20

43

X ray microimaging by diffractive techniques  

NASA Astrophysics Data System (ADS)

The first year of the research program resulted in significant progress on several fronts. The soft x ray undulator beamline, X1A, at the National Synchrotron Light Source became operational shortly before the start of the grant period. In microimaging by diffraction, Dr. David Sayre was successful in recording moderately large angle diffraction patterns from single diatom specimens. The patterns correspond to information down to the 70A level, and are by far the best achieved to date. To obtain these, a new diffraction camera was constructed and commissioned. It features a multiple pinhole collimator to define a 10 micron diameter beam, and an alignment system to position the 2 micron specimen within it.

44

In-line x-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite-cementite microstructure in steel  

NASA Astrophysics Data System (ADS)

This work presents the development of a non-destructive imaging technique for the investigation of the microstructure of cementite grains embedded in a ferrite matrix of medium-carbon steel. The measurements were carried out at the material science beamline of the European Synchrotron Radiation Facility (ESRF) ID11. It was shown that in-line X-ray phase-contrast tomography (PCT) can be used for the detection of cementite grains of several microns in size. X-ray PCT of the cementite structure can be achieved by either a `single distance' or a `multiple distance' acquisition protocol. The latter permits quantitative phase retrieval. A second imaging technique, X-ray diffraction-contrast tomography (DCT), was employed to obtain information about the shapes and crystallographic orientations of the distinct ferrite grains surrounding the cementite structures. The initial results demonstrate the feasibility of determining the geometry of the cementite grains after the austenite-ferrite phase-transformation in a non-destructive manner. The results obtained with PCT and DCT are verified with ex-situ optical microscopy studies of the same specimen.

Kostenko, Alexander; Sharma, Hemant; Dere, E. Gözde; King, Andrew; Ludwig, Wolfgang; Oel, Wim Van; Offerman, S. Erik; Stallinga, Sjoerd; Vliet, Lucas J. van

2012-05-01

45

Diffraction-limited astronomical X-ray imaging and X-ray interferometry using normal-incidence multilayer optics  

Microsoft Academic Search

We describe a new technical approach for observations of Galactic and extra-Galactic soft X-ray sources with ultra-high angular resolution. The technique is based on the use of recently developed (and commercially available) diffraction-limited, normal-incidence mirror substrates, and ultra-short-period multilayer coatings tuned to specific bright emission lines in the range 16-40 A, for the construction of a diffraction-limited X-ray telescope. Sub-milliarcsecond

D. L. Windt; G. E. Sommargren

2003-01-01

46

Diffraction-limited astronomical X-ray imaging and X-ray interferometry using normal-incidence multilayer optics  

Microsoft Academic Search

We describe a new technical approach for observations of Galactic and extra-Galactic soft X-ray sources with ultra-high angular resolution. The technique is based on the use of recently developed diffraction-limited, normal-incidence mirror substrates and ultra-short-period multilayer coatings, tuned to specific bright emission lines in the range 16 < l < 40 Å, for the construction of a diffraction-limited X-ray telescope.

David L. Windt; Steven M. Kahn; Gary E. Sommargren

2003-01-01

47

Diffraction-limited astronomical X-ray imaging and X-ray interferometry using normal-incidence multilayer optics  

Microsoft Academic Search

We describe a new technical approach for observations of Galactic and extra-Galactic soft X-ray sources with ultra-high angular resolution. The technique is based on the use of recently developed diffraction-limited, normal- incidence mirror substrates and ultra-short-period multilayer coatings, tuned to specific bright emission lines in the range 16 < ? < 40 Å, for the construction of a diffraction-limited X-ray

David L. Windt; Steven M. Kahn; Gary E. Sommargren

48

X-ray resonant powder diffraction  

NASA Astrophysics Data System (ADS)

X-ray resonant diffraction can be applied in structural chemistry studies on powder samples. It enables an important limitation of powder diffraction to be overcome. This limitation is related to the low ability of powder diffraction to differentiate elements with close atomic numbers when they occupy the same or close crystallographic sites (mixed occupancy case) and also to discriminate cations with different valence states in different sites. However the resonant effect usually has a second order influence on the measured intensity. As a consequence, the efficiency of this method directly implies the need for excellent quality data collection and has generally been better assessed on elements present in single phase powder samples. In recent years, instrumental developments have been made in synchrotron radiation facilities which allow easier use of resonant powder diffraction for site-specific contrast and valence i.e. oxidation state analyses. Moreover, resonant contrast diffraction tools also have been proposed for better visualization of the anomalous effect both in direct and reciprocal space by using differences between electron density maps or diffraction patterns. Finally the potentialities of this technique for de novo structure solution on macromolecular systems are mentioned.

Palancher, H.; Bos, S.; Bérar, J. F.; Margiolaki, I.; Hodeau, J. L.

2012-06-01

49

Ultrafast X-ray diffraction and X-ray absorption spectroscopy  

Microsoft Academic Search

Summary form only given. Recently developed ultrafast laser-driven X-ray sources enable the observation of atomic motions in crystals and in solutions on the timescale of chemical bond formation and breakage. Using such a laboratory-based X-ray source the propagation of coherent phonon wave packets through GaAs(111) crystals after photo excitation has been imaged by ultrafast X-ray difraction. While ultrafast x-ray diffraction

C. Rose-Petruck

2000-01-01

50

X-ray diffraction without sample preparation  

NASA Astrophysics Data System (ADS)

The author has recently invented a novel X-ray diffraction (XRD) technique which exhibits almost complete insensitivity to the sample morphology. This unique property allows XRD analysis of rocks and regolith while avoiding the need for resourceintensive and technically-challenging lander/rover sample preparation and distribution systems. The technique implements energy-dispersive XRD (EDXRD) in a back-reflection geometry. The intrinsic geometry of the method and the simplicity inherent to EDXRD enables a compact lightweight instrument design with no moving parts, suitable for deployment on a robotic arm. Details of the concept are presented here, along with a method to uncover diffraction peaks which are otherwise obscured by fluorescence peaks.

Hansford, G. M.

2012-09-01

51

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

Microsoft Academic Search

Several techniques involving X-rays are routinely applied in the study of works of art. These include radiography, X-ray diffraction, and X-ray fluorescence (often coupled with an electron beam instrument such as a scanning electron microscope or microprobe). Radiography provides information on condition and previous restorations or repairs. In the case of sculptures, the technique also sheds light on the manufacturing

Richard Newman

1998-01-01

52

Transient x-ray diffraction and its application to materials science and x-ray optics  

SciTech Connect

Time resolved x-ray diffraction and scattering have been applied to the measurement of a wide variety of physical phenomena from chemical reactions to shock wave physics. Interest in this method has heightened in recent years with the advent of versatile, high power, pulsed x-ray sources utilizing laser plasmas, electron beams and other methods. In this article, we will describe some of the fundamentals involved in time resolved x-ray diffraction, review some of the history of its development, and describe some recent progress in the field. In this article we will emphasize the use of laser-plasmas as the x-ray source for transient diffraction.

Hauer, A.A.; Kopp, R.; Cobble, J.; Kyrala, G.; Springer, R. [and others

1997-12-01

53

False Lines in X-Ray Grating Spectra  

Microsoft Academic Search

Because of the arrangement of slits, x-ray source and diffraction grating generally employed in x-ray spectroscopy, certain false lines may be obtained on the photographic plate in addition to those due to defects in the grating. Spectrograms of such spurious lines having their origin in a non-uniformfocal spot or reflection fromslit faces, as well as those due to certain grating

J. M. Cork

1930-01-01

54

Diffraction-limited large x-ray optics.  

PubMed

It is shown that the technologies required to produce large normal-incidence multilayer x-ray mirrors with diffraction-limited resolution are now available. Applications of these mirrors in x-ray astronomy and x-ray lithography are discussed. PMID:21307459

Spiller, E

1994-01-01

55

Element-specific hard x-ray diffraction microscopy  

NASA Astrophysics Data System (ADS)

An element-specific coherent x-ray imaging technique using anomalous x-ray scattering in the hard x-ray region was first demonstrated. Coherent x-ray diffraction patterns of a sample composed of 500-nm-thick Ni and Cu layers were measured at incident x-ray energies around the NiK absorption edge. Non-center-symmetric diffraction patterns due to anomalous scattering phenomenon in the hard x-ray region were observed. Symmetricity of the diffraction pattern was quantitatively analyzed by numerically simulating the x-ray wave field behind the sample position using the Rytov approximation. By calculating the difference between the intensities of reconstructed images of different energies, an image of the Ni layers could be derived although it was not enough to identify precisely. This method is widely applicable to nondestructive analysis of nanometer-scale elemental distribution of materials buried within thick and high- Z samples.

Takahashi, Yukio; Kubo, Hideto; Furukawa, Hayato; Yamauchi, Kazuto; Matsubara, Eiichiro; Ishikawa, Tetsuya; Nishino, Yoshinori

2008-09-01

56

Phase retrieval in x-ray coherent Fresnel projection-geometry diffraction  

SciTech Connect

Coherent x-ray diffraction experiments were performed in Fresnel regime, within a line-projection geometry. A planar x-ray waveguide was used to focus coherent cylindrical waves onto a 7.2 {mu}m Kevlar fiber, which acts as a phase object for hard x rays. The phase was retrieved, by using a Fourier-based iterative phasing algorithm, consistent with measured diffraction data and known constraints in real space, with a submicrometer spatial resolution.

De Caro, Liberato; Giannini, Cinzia; Cedola, Alessia; Pelliccia, Daniele; Lagomarsino, Stefano; Jark, Werner [Istituto di Cristallografia-Consiglio Nazionale delle Ricerche (IC-CNR), via Amendola 122/O, I-70126 Bari (Italy); Istituto di Fotonica e Nanotecnologie-Consiglio Nazionale delle Ricerche (IFN-CNR), via Cineto Romano 42, I-00156 Roma (Italy); Sincrotrone Trieste, S.S. 14 km 163.5, I-34012 Basovizza (TS) (Italy)

2007-01-22

57

Nanostructure Analysis using Coherent X-ray Diffraction  

NASA Astrophysics Data System (ADS)

X-ray crystallography can routinely determine the atomic structure of crystalline materials. The method can be extended to non-crystalline materials by using coherent X-ray diffraction. In X-ray diffraction microscopy, coherent X-ray diffraction patterns are sampled finely enough to satisfy the oversampling condition for solving the phase problem, and the iterative phase retrieval method is used for the sample image reconstruction. Recently, we succeeded in three-dimensional visualization of an unstained human chromosome by X-ray diffraction microscopy. It is the first hard X-ray tomography for cellular organelles. The reconstructed images revealed the internal axial structure, demonstrating an excellent image-contrast of the method.

Nishino, Yoshinori

58

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

National Technical Information Service (NTIS)

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

D. F. Blake

1999-01-01

59

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

Microsoft Academic Search

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

David F. Blake

60

Fabrication of diffractive optical elements for x-ray range  

Microsoft Academic Search

Problems of microelectronics technology applications for diffractive optical elements fabrication have been considered. The results on x-ray diffractive focusing elements are described: amplitude and phase-contrast Fresnel zone plates as well as freestanding gold gratings. The creation of reflected Bragg-Fresnel lenses for soft x-ray range was made on the basis of multilayer x-ray mirrors. Considerable attention was paid to the correction

Yu A. Agafonov; Sergey V. Babin; Alexei I. Erko; A. A. Shestakov; Igor A. Schelokov

1993-01-01

61

Fabrication of diffractive optical elements for x-ray range  

NASA Astrophysics Data System (ADS)

Problems of microelectronics technology applications for diffractive optical elements fabrication have been considered. The results on x-ray diffractive focusing elements are described: amplitude and phase-contrast Fresnel zone plates as well as freestanding gold gratings. The creation of reflected Bragg-Fresnel lenses for soft x-ray range was made on the basis of multilayer x-ray mirrors. Considerable attention was paid to the correction of different distortion factors involved in the electron beam lithography process.

Agafonov, Yu A.; Babin, Sergey V.; Erko, Alexei I.; Shestakov, A. A.; Schelokov, Igor A.

1993-12-01

62

X-Ray Diffraction Identification of Clay Minerals by Microcomputer.  

National Technical Information Service (NTIS)

The identification of clay minerals by X-ray powder diffraction are done by searching an unknown pattern with a file of standard X-ray diffraction patterns. For this searching done by hand is necessary a long time. This paper shows a program in ''Basic'' ...

S. Rodrigues F. J. Imasava

1988-01-01

63

X-RAY DIFFRACTION STUDIES ON FROG MUSCLES.  

PubMed

1. X-ray diffraction studies of sartorius muscles of Rana pipiens were made in a new x-ray diffraction camera which permits exposures of 3 to 6 minutes. The object-film distance can be varied from 20 to 80 mm; the muscle inside the camera can be electrically stimulated while contracting isotonically or isometrically, and can be observed by a special device. After exposures up to 30 minutes (approximately 40,830 r) muscles are still alive and responsive. 2. Contrary to the x-ray diffraction pattern of powdered dry muscle, which pattern consists of two rings corresponding to spacings of 4.46 A.u. and 9.66 A.u., both moist and dried whole sartorius muscle show signs of orientation in both rings, consisting of two equatorial streaks (wet) or points (dry) and meridional sickles. The moist muscle shows in addition a diffuse water ring. The spacings corresponding to the orientation points and elliptical structure show only slight differences in moist and dried samples. Through statistical computations based on two different series consisting of thirteen moist and twenty-eight dried samples, and nine muscles before and after drying, it was shown that only the divergence in the smaller spacing has some real significance, which indicates that most water of the moist muscle is bound intermolecularly. Upon resoaking of dried muscle the x-ray diffraction pattern of the moist muscle is restored. 3. Stretching of muscle by weights below the breaking point produces an additional well defined diffraction line, corresponding to a spacing of 4.32 A.u. A similar diffraction line can be produced in frog tendon upon stretching. 4. The influence of heat on the x-ray diffraction pattern of muscle depends upon the maximum temperature and the length of action; 5 minutes at 50 degrees C. markedly reduces the orientation of the sample; 5 minutes' immersion in boiling Ringer's solution destroys the orientation and produces a ring corresponding to a spacing of 5.3 to 5.5 A.u. in the moist and sharpening of the backbone reflection in the dried specimen. 5. Ultraviolet light brings forth changes in the x-ray diffraction pattern varying with the intensity of the irradiation. Ultimately a disappearance of the equatorial points and of the outside sickles is achieved while the elliptical shape of the outside ring and its diffuseness persist. In addition two salt rings characteristic of NaCl indicate that the irradiated muscles have become permeable to the surrounding medium (Ringer's solution). 6. Both faradic and single shock electrical stimulation were tried on muscles. If shortening of the muscle is prevented either by sufficient weight or by tying the muscle in a frame, no changes in the x-ray diffraction pattern occur; if the muscle is allowed to shorten without weights or by using insufficient weights, then the orientation either disappears completely or partially. When the muscle is stretched while contracted by electrical stimulation the orientation of the x-ray diffraction pattern reappears. 7. A number of salts with uni- and bivalent ions in concentrations corresponding osmotically to 0.73 per cent NaCl and 10 per cent NH(4)Cl were studied in their effects upon the x-ray diffraction of muscles. Of the salts with univalent ions in the lower concentration only KCl causes a marked decrease of orientation and an increase in the permeability of the fiber membranes. Similar effects on the orientation seem to be produced by CaCl(2) while MgCl(2) causes rather a more pronounced orientation. At hypertonic salt concentrations the orientation disappears completely and the corresponding salt rings become visible. Besides, NaCNS seems to have a specific effect on the outside ring and LiCl produces a ring at 21.3 A.u. and a splitting of the outside ring. 8. Strong mineral and lactic acids in concentrations up to 0.005 N have little if any influence upon the x-ray diffraction of muscles. A further increase in acidity to 0.01 N and above destroys the orientation completely, causes sharpening of the backbone reflection, and increased membrane permeability. These

Spiegel-Adolf, M; Henny, G C; Ashkenaz, E W

1944-11-20

64

X-ray powder diffraction study of polytetrafluoroethylene  

SciTech Connect

Samples of polytetrafluoroethylene were studied by X-ray diffraction. A quantitative X-ray powder diffraction analysis of three components of the polymer was performed for the first time. All samples of polytetrafluoroethylene were found to be three-phase and consist of one crystalline and two amorphous phases. One of the amorphous phases is composed of low-molecular-weight products. The structure of the latter phase was established for the first time by X-ray diffraction methods and computer simulation.

Lebedev, Yu. A., E-mail: y_levedev@mail.ru; Korolev, Yu. M. [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation); Polikarpov, V. M. [Tambov State Technical University (Russian Federation); Ignat'eva, L. N. [Russian Academy of Sciences, Institute of Chemistry, Far East Division (Russian Federation); Antipov, E. M. [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation)

2010-07-15

65

Fabrication of high-resolution x-ray diffractive optics at King's College London  

Microsoft Academic Search

The fabrication of high resolution x-ray diffractive optics, and Fresnel zone plates (ZPs) in particular, is a very demanding multifaceted technological task. The commissioning of more (and brighter) synchrotron radiation sources, has increased the number of x-ray imaging beam lines world wide. The availability of cheaper and more effective laboratory x-ray sources, has further increased the number of laboratories involved

Pambos S. Charalambous; Peter A. Anastasi; Ronald E. Burge; Katia Popova

1995-01-01

66

Tunable diffractive optical elements for hard x-rays  

Microsoft Academic Search

We describe the fabrication and testing of a novel type of tunable transmission hard x-ray optics. The diffractive elements are generated by electron beam lithography and chemical wet etching of oriented silicon substrates. Structures with widths down to 100 nm and extreme aspect ratios were obtained using this method. By tilting the lenses with respect to the x-ray beam, the

Christian David; Bernd Noehammer; Eric Ziegler; Olivier Hignette

2001-01-01

67

Wavelength tunable diffractive transmission lens for hard x rays  

Microsoft Academic Search

We report on the fabrication and testing of linear transmission Fresnel zone plates for hard x rays. The diffractive elements are generated by electron beam lithography and chemical wet etching of oriented silicon substrates. By tilting the cylindrical lenses with respect to the x-ray beam, the effective path through the phase shifting zones can be varied. This makes it possible

C. David; B. Nöhammer; E. Ziegler

2001-01-01

68

Diffractive–refractive X-ray optics for very high angular resolution X-ray astronomy  

Microsoft Academic Search

The 0.5arcsec angular resolution of the Chandra X-ray Observatory is possibly the best that a grazing incidence telescope with substantial collecting area will ever attain. We describe a telescope consisting of a diffractive and refractive doublet that transmits rather than reflects X-rays. Therefore, its angular resolution is relatively insensitive to figure errors and surface roughness, the factors that limit grazing

Paul Gorenstein

2007-01-01

69

An X-ray diffraction and X-ray absorption spectroscopy joint study of neuroglobin  

Microsoft Academic Search

Neuroglobin (Ngb) is a member of the globin family expressed in the vertebrate brain, involved in neuroprotection. A combined approach of X-ray diffraction (XRD) on single crystal and X-ray absorption spectroscopy (XAS) in solution, allows to determine the oxidation state and the structure of the Fe–heme both in the bis-histidine and the CO-bound (NgbCO) states. The overall data demonstrate that

Alessandro Arcovito; Tommaso Moschetti; Paola D’Angelo; Giordano Mancini; Beatrice Vallone; Maurizio Brunori; Stefano Della Longa

2008-01-01

70

Multiwavelength Anomalous Diffraction at High X-Ray Intensity  

NASA Astrophysics Data System (ADS)

The multiwavelength anomalous diffraction (MAD) method is used to determine phase information in x-ray crystallography by employing anomalous scattering from heavy atoms. X-ray free-electron lasers (FELs) show promise for revealing the structure of single molecules or nanocrystals, but the phase problem remains largely unsolved. Because of the ultrabrightness of x-ray FEL, samples experience severe electronic radiation damage, especially to heavy atoms, which hinders direct implementation of MAD with x-ray FELs. Here, we propose a generalized version of MAD phasing at high x-ray intensity. We demonstrate the existence of a Karle-Hendrickson-type equation in the high-intensity regime and calculate relevant coefficients with detailed electronic damage dynamics of heavy atoms. The present method offers a potential for ab initio structural determination in femtosecond x-ray nanocrystallography.

Son, Sang-Kil; Chapman, Henry N.; Santra, Robin

2011-11-01

71

Small Angle X-Ray Diffraction from Crystalline Polymers.  

National Technical Information Service (NTIS)

Small angle x-ray diffraction and electron microscopic examinations were made of crystalline bulk polymers (polyethylene and polyoxyethylene) with particular respect to crystal thickness and regularity. Major problems attendant to pattern interpretation a...

P. H. Geil A. Burmester

1970-01-01

72

Fabrication of X-ray Mirror for Hard X-ray Diffraction Limited Nanofocusing  

SciTech Connect

We designed, fabricated and evaluated a total-reflection mirror having a designed focal size of 28 nm at 15keV. Line-focus tests on the fabricated mirror were carried out at the 1-km-long beamline (BL29XUL) of SPring-8. Nearly diffraction-limited performance with a full width at half maximum spot size of 30 nm was realized at 15 keV. We are planning to fabricate multilayer-coated mirror for realizing sub-10-nm focusing in hard x-ray region. We suggest a novel method of at-wavelength metrology. Wave-front error on the mirror surface can be estimated by a phase retrieval method using the intensity profile around the focal point. By correcting the estimated wave-front errors, sub-10-nm focusing is potentially feasible.

Yumoto, Hirokatsu; Mimura, Hidekazu; Matsuyama, Satoshi; Handa, Soichiro; Shibatani, Akihiko; Katagishi, Keiko; Yamamura, Kazuya; Sano, Yasuhisa; Endo, Katsuyoshi; Mori, Yuzo; Yamauchi, Kazuto [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Yabashi, Makina [SPring-8/Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Nishino, Yoshinori; Tamasaku, Kenji; Ishikawa, Tetsuya [SPring-8/RIKEN, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)

2007-01-19

73

Simulations of X-ray photoelectron diffraction for polytype analysis  

Microsoft Academic Search

Single scattering cluster (SSC) simulations are used to explore the possibilities and the limitations of X-ray photoelectron diffraction (XPD) with standard laboratory X-ray sources in the field of polytype determination of silicon carbide (SiC) films. We show that the bulk emission dominates the diffraction patterns at energies of more than 1 keV. Effects due to surface reconstructions can be ignored

Aimo Winkelmann; Bernd Schröter; Wolfgang Richter

2002-01-01

74

X-ray diffraction assisted spectroscopy of Rydberg states  

SciTech Connect

X-ray diffraction combined with conventional spectroscopy could provide a powerful means to characterize electronically excited atoms and molecules. We demonstrate theoretically how x-ray diffraction from laser excited atoms can be used to determine electronic structure, including angular momentum composition, principal quantum numbers, and channel populations. A theoretical formalism appropriate for highly excited atoms, and easily extended to molecules, is presented together with numerical results for Xe and H atoms.

Kirrander, Adam [ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States)

2012-10-21

75

Microbeam X-Ray Standing Wave and High Resolution Diffraction  

SciTech Connect

Post-focusing collimating optics are introduced as a tool to condition X-ray microbeams for the use in high-resolution X-ray diffraction and scattering techniques. As an example, a one-bounce imaging capillary and miniature Si(004) channel-cut crystal were used to produce a microbeam with 10 {mu}m size and an ultimate angular resolution of 2.5 arc sec. This beam was used to measure the strain in semiconductor microstructures by using X-ray high resolution diffraction and standing wave techniques to {delta}d/d < 5x10-4.

Kazimirov, A.; Bilderback, D.H.; Huang, R. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); Sirenko, A. [New Jersey Institute of Technology, Department of Physics, Newark, NJ 07102 (United States)

2004-05-12

76

White lines in L-edge x-ray absorption spectra and their implications for anomalous diffraction studies of biological materials.  

PubMed Central

We have measured high-resolution x-ray absorption spectra of lanthanide (Ln) and heavy transition metal complexes that display prominent narrow absorption peaks near the L2 and L3 absorption edges. The anomalous scattering factors (f' and f"), which are mathematically related to the absorption cross section, have correspondingly sharp changes in their magnitude within 5-10 eV of the absorption edge. Calculations of the magnitude of the change in f' and f" demonstrate that significant changes (on the order of 20 electrons in f') can be expected for these materials. These substantial changes in the anomalous scattering factors have applications to deriving structural information for macromolecules from x-ray diffraction studies. The magnitude of the changes indicate that the anomalous scattering technique is a powerful means of obtaining structural characteristics for macromolecules in single crystals, in solution, and in biological membranes.

Lye, R C; Phillips, J C; Kaplan, D; Doniach, S; Hodgson, K O

1980-01-01

77

Transient x-ray diffraction to measure the dynamic response of shocked lithium fluoride single crystal  

NASA Astrophysics Data System (ADS)

Transient x-ray diffraction, also called time-resolved x-ray diffraction and dynamic x-ray diffraction, is one novel diagnostic technique for probing shocked solids. It can provide direct information about microscopic mechanisms governing shock-induced deformation and structural changes at atomistic scales with nanosecond and picoseconds resolution, and lately, it has become possible to measure the structure of transients with sub-picoseconds and sub-Angstrom resolution with the development of ultrafast lasers which can produce femtosecond electron and x-ray pulses in the form of characteristics emission lines as well as x-ray continua in the keV range. In this paper, we detect and measure directly the dynamic response of lithium fluoride single crystal shocked compressed by laser irradiation in SHENGUANG II. In our experiments, high-intensity lasers irradiated a thin Cu foil to generate helium-like rays as x-ray source. Film (IP--image plate) recorded x rays diffracted from multiple lattice planes both perpendicular and oblique angles to the shock loading direction [100]. We gained the diffraction signals of the lattice planes (200) shocked and unshocked, what's more, other lattices (113), (1-13). The positions of the diffraction lines associated with the (200) lattice plane indicated compression of the lattice along [100] direction by 13%. In the experiment, a large-angle detector consists of two films-one rectangular in shape,one triangular in shape that are positioned to record x rays diffracted from a shocked single crystal nearly within a full ? steradian. The experiment shows that transient x-ray diffraction can diagnose the dynamical response of solid with higher resolution.

Wang, Hai-rong; Ye, Yan; Yang, Qing-guo; Li, Mu; Xiao, Sha-li; Li, Ze-ren

2013-08-01

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

1992-02-01

79

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

2011-12-31

80

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.

Lima, Enju; Wiegart, Lutz; Pernot, Petra; Howells, Malcolm; Timmins, Joanna; Zontone, Federico; Madsen, Anders [European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble (France)

2009-11-06

81

Coherent grating x-ray diffraction (CGXD) and its applications  

SciTech Connect

We show that an x-ray interference phenomenon, coherent grating x-ray diffraction (CGXD), can be used to study lateral nanostructure arrays on crystal surfaces and interfaces. Compared to Fraunhofer grating diffraction of visible light, x-ray grating diffraction contains information not only about geometric profiles of the surface but also about the internal crystalline structures and lattice strain distributions in the grating features. The grating diffraction pattern can also be measured in a white-beam Laue method using highly collimated polychromatic synchrotron radiation, which provides a parallel data collection scheme and may be useful in {ital in} {ital situ} studies on evolution of nanostructure arrays. {copyright} {ital 1996 American Institute of Physics.}

Shen, Q. [Cornell High Energy Synchrotron Source (CHESS) and School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States)

1996-09-01

82

Tutorial on x-ray microLaue diffraction  

SciTech Connect

MicroLaue diffraction combines the oldest x-ray diffraction method-Laue diffraction-with the most modern x-ray sources, optics and detectors. The combination can resolve complex materials into single-crystal-like submicron volumes. This unique ability to nondestructively map crystal structure at and below a sample surface, with high spatial and strain resolution can address long-standing fundamental issues in materials science. For example, the three-dimensional evolution of mesoscale structure and the self organization of defects can be observed nondestructively to understand the origins of inhomogeneous grain growth, deformation and fracture.

Ice, Gene E., E-mail: IceGE@ornl.gov [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6118 (United States); Pang, Judy W.L. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6118 (United States)

2009-11-15

83

Tutorial on x-ray microLaue diffraction  

SciTech Connect

MicroLaue diffraction combines the oldest x-ray diffraction method--Laue diffraction--with the most modern x-ray sources, optics and detectors. The combination can resolve complex materials into single-crystal-like submicron volumes. This unique ability to nondestructively map crystal structure at and below a sample surface, with high spatial and strain resolution can address long-standing fundamental issues in materials science. For example, the three-dimensional evolution of mesoscale structure and the self organization of defects can be observed nondestructively to understand the origins of inhomogeneous grain growth, deformation and fracture.

Ice, Gene E [ORNL; Pang, Judy [ORNL

2009-01-01

84

Real-time x-ray diffraction measurements of shocked polycrystalline tin and aluminum  

Microsoft Academic Search

A new, fast, single-pulse x-ray diffraction (XRD) diagnostic for determining phase transitions in shocked polycrystalline materials has been developed. The diagnostic consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, producing line and bremsstrahlung x-ray emission in a 35 ns pulse. The characteristic Kalpha lines from the selected anodes of

Dane V. Morgan; Don Macy; Gerald Stevens

2008-01-01

85

Flash X-Ray Diffraction System for Ultrafast Temperature and Phase Transition Measurements  

SciTech Connect

A novel ultrafast diagnostic for determining bulk temperature and phase transitions for polycrystalline metal objects has been developed. The diagnostic consists of a 38-stage Marx bank with a cable-coupled X-ray diode that produces a 35-ns pulse of mostly 0.71 Å monochromatic X rays, and a P-43 fluor coupled to a cooled charge-coupled device camera by a coherent fiber-optic bundle for detection of scattered X rays. The X-ray beam is collimated to a 1° divergence in the scattering plane with the combination of a 1.5-mm tungsten pinhole and a 1.5-mm diameter molybdenum anode. The X-ray diode, in a needle-and-washer configuration, is heavily shielded in all directions other than the collimated beam. The X-ray diode has a sealed reentrant system, which allows the X rays to be produced inside a vacuum containment vessel, close to the sample under study. The direct correlation between the solid-state structure and the coherent X-ray diffraction pattern from a metal surface allows an unequivocal determination of a phase transition. This correlation has been tested in the laboratory with samples of indium and tin. For both metals, diffraction lines were observed at temperatures just below the melt temperature, along with background consisting of Compton scattering and sample fluorescence. Upon melt, the diffraction lines were observed to disappear; however, the background from Compton scattering and sample fluorescence remained. Flash X-ray diffraction also enables direct ultrafast measurements of the bulk temperature of the sample under study. According to the Debye-Waller theory, the diffracted line intensity reduces as the temperature of the sample increases. The amplitude of the reduced diffracted signal also depends on the Debye temperature of the sample, the scattering angle of the diffracted X rays, and the X-ray wavelength. The feasibility of using the Debye-Waller theory for flash X-ray diffraction measurements of the bulk temperature is currently being studied.

Dane Morgan, Don Macy, Michael Madlener, Jaiming Morgan

2007-06-01

86

New aspect of diffraction of a highly divergent characteristic X-ray beam  

SciTech Connect

A new way of implementing the diffraction of a highly divergent characteristic X-ray beam has been developed. This method is based on the formation of a diffraction image by the X rays exiting particular (active) points on the crystal surface which lie on hyperbolas. There is a correspondence between the points on the crystal surface and the points in the diffraction image. Local distortions of the crystal structure lead to local deviations of the diffraction lines from proper hyperbolas. This method makes it possible to reveal the block structure of crystals, separate blocks, and estimate the degree of misorientation.

Avetyan, K. T., E-mail: marakelyan@ysu.am [Yerevan State University (Armenia)

2010-09-15

87

High-resolution Hard-x-ray Microscopy using Second-order Zone-plate Diffraction  

SciTech Connect

Odd-order diffraction of zone plates (ZPs) is already used for x-ray microscopy but the potential offered by even-order diffraction must still be fully exploited. Width differences between lines and interline spaces transfer intensity from odd-order to even-order diffractions. Here we show that the resulting intense second-order diffraction provides a reasonable tradeoff between spatial resolution and intensity - and constitutes a viable strategy for x-ray microscopy to reach sub-20 nm resolution, in spite of the imperfections of high-aspect-ratio ZPs and of other difficulties.

J Yi; Y Chu; Y Chen; T Chen; Y Hwu; G Margaritondo

2011-12-31

88

Towards high-resolution ptychographic x-ray diffraction microscopy  

NASA Astrophysics Data System (ADS)

Ptychographic x-ray diffraction microscopy is a lensless imaging technique with a large field of view and high spatial resolution, which is also useful for characterizing the wavefront of an x-ray probe. The performance of this technique is degraded by positioning errors due to the drift between the sample and illumination optics. We propose an experimental approach for correcting the positioning errors and demonstrate success by two-dimensionally reconstructing both the wavefront of the focused x-ray beam and the complex transmissivity of the weakly scattering objects at the pixel resolution of better than 10 nm in the field of view larger than 5 ?m. This method is applicable to not only the observation of organelles inside cells or nano-mesoscale structures buried within bulk materials but also the characterization of probe for single-shot imaging with x-ray free electron lasers.

Takahashi, Yukio; Suzuki, Akihiro; Zettsu, Nobuyuki; Kohmura, Yoshiki; Senba, Yasunori; Ohashi, Haruhiko; Yamauchi, Kazuto; Ishikawa, Tetsuya

2011-06-01

89

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

1997-09-01

90

X-ray diffraction-based electronic structure calculations and experimental x-ray analysis for medical and materials applications  

Microsoft Academic Search

This thesis includes x-ray experiments for medical and materials applications and the use of x-ray diffraction data in a first-principles study of electronic structures and hyperfine properties of chemical and biological systems. Polycapillary focusing lenses were used to collect divergent x rays emitted from conventional x-ray tubes and redirect them to form an intense focused beam. These lenses are routinely

Dip Narayan Mahato

2009-01-01

91

An X-ray diffraction study of the effects of heat treatment on bone mineral microstructure  

Microsoft Academic Search

A series of human cortical bone specimens has been heated to temperatures up to 1200°C and the mineral content examined in detail by X-ray diffraction. Line profile analysis of the diffraction data has been undertaken to characterise the microstructural (crystallite size and microstrain) features of the mineral at each temperature. Individual profile fitting of several maxima from each diffractogram has

K. D. Rogers; P. Daniels

2002-01-01

92

X-Ray Diffraction Project Final Report, Fiscal Year 2006  

SciTech Connect

An x-ray diffraction diagnostic system was developed for determining real-time shock-driven lattice parameter shifts in single crystals at the gas gun at TA-IV at Sandia National Laboratories (SNL). The signal-to-noise ratio and resolution of the system were measured using imaging plates as the detector and by varying the slit width. This report includes tests of the x-ray diffraction system using a phosphor coupled to a charge-coupled device (CCD) camera by a coherent fiber-optic bundle. The system timing delay was measured with a newly installed transistor-transistor logic (TTL) bypass designed to reduce the x-ray delay time. The axial misalignment of the Bragg planes was determined with respect to the optical axis for a set of eight LiF [lithium fluoride] crystals provided by SNL to determine their suitability for gas gun experiments.

Dane V. Morgan

2006-10-01

93

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)

2010-06-23

94

X-ray monitoring of NGC~4507: X-ray absorption by Broad Line Clouds  

Microsoft Academic Search

We propose a new XMM-Newton monitoring of the X-ray obscured AGN in NGC~4507, with the aim of testing a scenario where the variable X-ray absorption is due to the broad emission line clouds. The identification of these two components is suggested by our previous monitoring of a few other sources (NGC 1365, NGC 4151, UGC 4203), where rapid X-ray absorption

Guido Risaliti

2009-01-01

95

X-Ray Photoelectron Diffraction. Possibilities of Surface Structural Analysis  

Microsoft Academic Search

The current state of the X-ray photoelectron diffraction (XPD) method and its applications to solid state surface chemistry are overviewed in a systematic way. The fundamentals of the method are presented along with a number of approaches to its description: plane wave and spherical wave single scattering approximation, spherical wave multiple scattering approximation, and direct scattering and s-photoelectron scattering approximation.

E. V. Shalaeva; M. V. Kuznetsov

2003-01-01

96

Quantitative Mineralogical Analysis by X-ray diffraction.  

National Technical Information Service (NTIS)

Work was done in two phases on different combinations of soil-like crystalline materials that were mixed in the laboratory to develop a simple, rapid, and inexpensive method of doing quantitative mineralogical analyses, largely by X-ray diffraction (XRD)....

A. D. Buck

1972-01-01

97

Coherent X-ray diffraction from collagenous soft tissues  

SciTech Connect

Coherent X-ray diffraction has been applied in the imaging of inorganic materials with great success. However, its application to biological specimens has been limited to some notable exceptions, due to the induced radiation damage and the extended nature of biological samples, the last limiting the application of most part of the phasing algorithms. X-ray ptychography, still under development, is a good candidate to overcome such difficulties and become a powerful imaging method for biology. We describe herein the feasibility of applying ptychography to the imaging of biological specimens, in particular collagen rich samples. We report here speckles in diffraction patterns from soft animal tissue, obtained with an optimized small angle X-ray setup that exploits the natural coherence of the beam. By phasing these patterns, dark field images of collagen within tendon, skin, bone, or cornea will eventually be obtained with a resolution of 60-70 nm. We present simulations of the contrast mechanism in collagen based on atomic force microscope images of the samples. Simulations confirmed the 'speckled' nature of the obtained diffraction patterns. Once inverted, the patterns will show the disposition and orientation of the fibers within the tissue, by enhancing the phase contrast between protein and no protein regions of the sample. Our work affords the application of the most innovative coherent X-ray diffraction tools to the study of biological specimens, and this approach will have a significant impact in biology and medicine because it overcomes many of the limits of current microscopy techniques.

Berenguer de la Cuesta, Felisa; Wenger, Marco P.E.; Bean, Richard J.; Bozec, Laurent; Horton, Michael A.; Robinson, Ian K.; (UCL)

2009-09-11

98

X-Ray Diffraction Simulation Using Laser Pointers and Printers.  

ERIC Educational Resources Information Center

|Uses a laser pointer to demonstrate the analogy between optical and X-ray diffraction and a laser printer with 600 or 1200 dot resolution to create and modify arrays, print them on transparencies, and illuminate them with laser pointers. Includes 14 references. (Author/YDS)|

Johnson, Neil E.

2001-01-01

99

X-ray diffraction from epitaxial multilayered surface gratings  

Microsoft Academic Search

X-ray diffraction from simple monocrystalline and epitaxial multilayered surface gratings will be described theoretically by use of a distorted wave Born approximation of second order. The intensity patterns of simple and multilayered gratings have been simulated by this treatment and compared with the kinematical approximation. The gratings act simultaneously as reflection and transmission gratings. This gives rise to Umweganregung also

G. T. Baumbach; M. Gailhanou

1995-01-01

100

Diffractive-refractive optics: X-ray collimator  

SciTech Connect

Diffractive-refractive optics are x-ray focusing monochromators based on the diffraction on profiled crystal surface. Diffraction on longitudinal parabolic groove machined in crystal surface forms a sagittaly focused synchrotron radiation beam. Such kind of monochromator may be realized as a crystal with parabolic hole, where the beam is diffracted on the inner wall of the hole. Two such asymmetrically cut crystals set into antiparallel position, creating a dispersive (+,-,-,+) arrangement, form a sagittaly focusing x-ray monochromator which should be practically aberration-free. The focusing properties of such kind of monochromator are discussed in detail and it is shown for the first time that it can be used not only for focusing but also for creating highly parallel monochromatic beam in the broad region of the Bragg angles. This device with parabolic hole has not been tested experimentally yet.

Hrdy, Jaromir; Oberta, Peter [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Praha 8 (Czech Republic)

2008-07-15

101

Diffractive-refractive optics: X-ray collimator  

NASA Astrophysics Data System (ADS)

Diffractive-refractive optics are x-ray focusing monochromators based on the diffraction on profiled crystal surface. Diffraction on longitudinal parabolic groove machined in crystal surface forms a sagittaly focused synchrotron radiation beam. Such kind of monochromator may be realized as a crystal with parabolic hole, where the beam is diffracted on the inner wall of the hole. Two such asymmetrically cut crystals set into antiparallel position, creating a dispersive (+,-,-,+) arrangement, form a sagittaly focusing x-ray monochromator which should be practically aberration-free. The focusing properties of such kind of monochromator are discussed in detail and it is shown for the first time that it can be used not only for focusing but also for creating highly parallel monochromatic beam in the broad region of the Bragg angles. This device with parabolic hole has not been tested experimentally yet.

Hrdý, Jaromír; Oberta, Peter

2008-07-01

102

Diffractive-refractive optics: X-ray collimator.  

PubMed

Diffractive-refractive optics are x-ray focusing monochromators based on the diffraction on profiled crystal surface. Diffraction on longitudinal parabolic groove machined in crystal surface forms a sagittaly focused synchrotron radiation beam. Such kind of monochromator may be realized as a crystal with parabolic hole, where the beam is diffracted on the inner wall of the hole. Two such asymmetrically cut crystals set into antiparallel position, creating a dispersive (+,-,-,+) arrangement, form a sagittaly focusing x-ray monochromator which should be practically aberration-free. The focusing properties of such kind of monochromator are discussed in detail and it is shown for the first time that it can be used not only for focusing but also for creating highly parallel monochromatic beam in the broad region of the Bragg angles. This device with parabolic hole has not been tested experimentally yet. PMID:18681689

Hrdý, Jaromír; Oberta, Peter

2008-07-01

103

X-ray diffraction peaks from partially ordered misfit dislocations  

SciTech Connect

We calculate the x-ray diffraction peak profiles from distributions of misfit dislocations in the whole range of their positional correlations, from completely random to periodic. Both the spatial integration and the integration over the dislocation ensemble are performed by Monte Carlo techniques. The diffraction peaks from thin relaxed films consisting of a narrow coherent and a broad diffuse component are explained. Correlation functions are calculated analytically for different types of positional correlations between dislocations.

Kaganer, Vladimir M.; Sabelfeld, Karl K. [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany); Institute of Computational Mathematics and Mathematical Geophysics, Russian Academy of Sciences, Lavrentiev Prosp. 6, 630090 Novosibirsk (Russian Federation)

2009-11-01

104

Wide angle X-ray diffraction topography of polycrystalline materials  

SciTech Connect

X-ray topography is characterized by the spatially resolved detection of scattering of a material. The advantages of radiographic imaging can be combined with the analytical information revealed by Wide Angle X-Ray Diffraction. Beyond the limitations of the well-known Single Crystal Topography new approaches by single beam scanning techniques under pre-selected scattering conditions permit the topographic characterization of polycrystalline or amorphous solids or liquids. The principles of different topographic methods and their application to polymer and ceramic composites are presented.

Hentschel, Manfred P.; Lange, Axel; Schors, Joerg; Wald, Oliver; Harbich, Karl-Wolfram [Federal Institute for Materials Research and Testing, BAM-VIII.32, D-12200 Berlin (Germany)

1999-12-02

105

X-ray line measurements with high efficiency Bragg crystals  

NASA Astrophysics Data System (ADS)

We have studied the focusing properties of two highly oriented pyrolitic graphite (HOPG) spectrometers, which differ in the degree of the mosaic spread: ZYA with a low mosaic spread (?=0.4°) and ZYH with a large mosaic spread (?=3.5°). In order to asses the crystal performance for a variety of different experiments, various K? and K? x-ray lines have been produced using a high-intensity (>~1017 W/cm2) short-pulse (~100 fs) laser beam focused onto Ti, V, Zn, and Cu foils. The measured spectral resolution of the HOPG crystals in both first and second order diffraction has been compared with theoretical predictions. Using known values for the peak reflectivity of HOPG crystals, we have also computed K? x-ray conversion efficiencies of Ti, V, Zn, and Cu. These results are important to estimate the optimal conditions under which different types of HOPG monochromators can be used for the detection of weak x-ray signals as the one encountered in x-ray Thomson/Compton scattering experiments.

Pak, A.; Gregori, G.; Knight, J.; Campbell, K.; Price, D.; Hammel, B.; Landen, O. L.; Glenzer, S. H.

2004-10-01

106

Diffraction peaks restoration and extraction in energy dispersive X-ray diffraction  

Microsoft Academic Search

This paper proposes a method to restore energy dispersive X-ray diffraction (EDXRD) spectra and to extract diffraction peaks. It follows a maximum a posteriori approach using a physical model of the formation of the EDXRD data to remove blur caused by both the detector and the coarse angular resolution of X-ray tube based EDXRD setup. It separates peaks due to

Ferréol Soulez; Charles Crespy; Valérie Kaftandjian; Philippe Duvauchelle

2011-01-01

107

Fabrication of Diffraction Grating with High Aspect Ratio Using X-ray Lithography Technique for X-ray Phase Imaging  

NASA Astrophysics Data System (ADS)

The use of conventional X-ray radiography is limited due to weak absorption. This problem is resolved by using phase-sensitive imaging methods to improve the contrast, such as X-ray Talbot interferometry. With a spatially coherent light source and two diffraction gratings for Talbot interferometry, we measured the phase change differential. Using this technique, diffraction gratings were designed to have a fine high-accuracy high-aspect-ratio structure. Then, we fabricated a high-aspect-ratio diffraction grating using a deep X-ray lithography technique. A diffraction grating with a period of 8 ?m and a height of about 30 ?m was fabricated. This diffraction grating can be used for X-ray phase imaging for X-ray Talbot interferometry.

Noda, Daiji; Tanaka, Makoto; Shimada, Kazuma; Hattori, Tadashi

2007-02-01

108

X-ray diffraction from intact tau aggregates in human brain tissue  

SciTech Connect

We describe an instrument to record X-ray diffraction patterns from diseased regions of human brain tissue by combining an in-line visible light fluorescence microscope with an X-ray diffraction microprobe. We use thiazine red fluorescence to specifically label and detect the filamentous tau protein pathology associated with Pick's disease, as several laboratories have done previously. We demonstrate that thiazine red-enhanced regions within the tissue show periodic structure in X-ray diffraction, which is not observed in healthy tissue. One observed periodicity (4.2 {angstrom}) is characteristic of cross-beta sheet structure, consistent with previous results from powder diffraction studies performed on purified, dried tau protein.

Landahl, Eric C.; Antipova, Olga; Bongaarts, Angela; Barrea, Raul; Berry, Robert; Binder, Lester I.; Irving, Thomas; Orgel, Joseph; Vana, Laurel; Rice, Sarah E. (DePaul); (IIT); (NWU)

2011-09-15

109

X-ray diffraction line profile analysis for defect study in Cu-1 wt.% Cr-0.1 wt.% Zr alloy  

SciTech Connect

X-ray line profile analysis (LPA) has been used for microstructural analysis of a Cu-1 wt.% Cr-0.1 wt.% Zr alloy. Using this technique, the stacking fault probability (SFP) and stacking fault energy (SFE) has been determined for the pure Cu and the Cu-1 wt.% Cr-0.1 wt.% Zr alloy. It is observed that there is an increase in the stacking fault probability (and corresponding decrease in stacking fault energy) in case of the alloy. The increased formation of faulted regions in the Cu-1 wt.% Cr-0.1 wt.% Zr alloy is supported by the observation of extended dislocation nodes and fringe contrast due to staking faults under TEM, and higher work hardening rate in the tension test. The high thermal fatigue resistance of this alloy is attributed to decrease in the stacking fault energy by addition of Cr and Zr to Cu.

Kapoor, K. [Advanced Materials Characterisation Laboratory, Nuclear Fuel Complex, Hyderabad 500 062 (India)]. E-mail: kapoork@nfc.ernet.in; Lahiri, D. [Advanced Materials Characterisation Laboratory, Nuclear Fuel Complex, Hyderabad 500 062 (India); Batra, I.S. [Materials Science Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 094 (India); Rao, S.V.R. [Advanced Materials Characterisation Laboratory, Nuclear Fuel Complex, Hyderabad 500 062 (India); Sanyal, T. [Advanced Materials Characterisation Laboratory, Nuclear Fuel Complex, Hyderabad 500 062 (India)

2005-02-15

110

Discovery and development of x-ray diffraction  

NASA Astrophysics Data System (ADS)

In 1912 Max Laue at University of Munich reasoned x-rays to be short wavelength electromagnetic waves and figured interference would occur when scattered off crystals. Arnold Sommerfeld, W. Wien, Ewald and others, raised objections to Laue's idea, but soon Walter Friedrich succeeded in recording x-ray interference patterns off copper sulfate crystals. But the Laue-Ewald's 3-dimensional formula predicted excess spots. Fewer spots were observed. William Lawrence Bragg then 22 year old studying at Cambridge University heard the Munich results from father William Henry Brag, physics professor at Univ of Leeds. Lawrence figured the spots are 2-d interference of x-ray wavelets reflecting off successive atomic planes and derived a simple eponymous equation, the Bragg equation d*sin(theta)= n*lamda. 1913 onward the Braggs dominated the crystallography. Max Laue was awarded the physics Nobel in 1914 and the Braggs shared the same in 1915. Starting with Rontgen's first ever prize in 1901, the importance of x-ray techniques is evident from the four out of a total 16 physics Nobels between 1901-1917. We will outline the historical back ground and importance of x-ray diffraction giving rise to techniques that even in 2013, remain work horses in laboratories all over the globe.

Jeong, Yeuncheol; Yin, Ming; Datta, Timir

2013-03-01

111

Simulations of a Johann/Johansson diffraction spectrometer for x-ray experiments at an electron beam ion source  

NASA Astrophysics Data System (ADS)

The ray tracing simulations of x-ray spectra for a compact six-crystal Johann/Johansson diffraction spectrometer covering a wide photon energy range (70 eV-15 keV), i.e. from the extended ultraviolet to the hard x-ray region, are discussed in the context of x-ray experiments at an electron beam ion source facility. In particular, the x-ray line profiles and energy resolution for different diffraction crystals and multilayers were studied, and the effects of extension of x-ray source size and misalignment were investigated. The simulations were also performed for x-ray emission from solid targets bombarded by electrons, which will be used for calibration of the x-ray spectrometer.

Jab?o?ski, ?.; Jagodzi?ski, P.; Bana?, D.; Pajek, M.

2013-09-01

112

Fabrication of x-ray diffractive optical elements for laser fusion applications  

NASA Astrophysics Data System (ADS)

We review our recent progress on the fabrication of x-ray diffractive optical elements (DOEs) by combining complementary advantages of electron beam, x-ray, and proximity optical lithography. First, an electron beam lithography tool with an accelerating voltage of 100 kV is used to expose initial x-ray mask based on SiC membrane with a low aspect ratio. Second, x-ray lithography is used to replicate x-ray DOEs and amplify the aspect ratio up to 14:1. Third, proximity optical lithography is used to fabricate a large-scale gold mesh as the supporting structures. We demonstrate that this method can achieve high aspect ratio metal nanometer structures without the need of a complicated multilayer resist process. A large number of x-ray DOEs have been fabricated with feature sizes down to 100 nm for the purpose of laser plasma fusion applications. Among them, the ninth-order diffraction peak on the positive side of the zeroth order can be observed for both 3333 and 5000 lines/mm x-ray gold transmission gratings.

Xie, Changqing; Zhu, Xiaoli; Li, Hailiang; Niu, Jiebin; Hua, Yilei; Shi, Lina

2013-03-01

113

Anomalous X-ray diffraction with soft X-ray synchrotron radiation.  

PubMed

Anomalous diffraction with soft X-ray synchrotron radiation opens new possibilities in protein crystallography and materials science. Low-Z elements like silicon, phosphorus, sulfur and chlorine become accessible as new labels in structural studies. Some of the heavy elements like uranium exhibit an unusually strong dispersion at their M(V) absorption edge (lambdaMV = 3.497 A, E(MV) = 3545 eV) and so does thorium. Two different test experiments are reported here showing the feasibility of anomalous X-ray diffraction at long wavelengths with a protein containing uranium and with a salt containing chlorine atoms. With 110 electrons the anomalous scattering amplitude of uranium exceeds by a factor of 4 the resonance scattering of other strong anomalous scatterers like that of the lanthanides at their L(III) edge. The resulting exceptional phasing power of uranium is most attractive in protein crystallography using the multi-wavelength anomalous diffraction (MAD) method. The anomalous dispersion of an uranium derivative of asparaginyl-tRNA synthetase (hexagonal unit cell; a = 123.4 A, c = 124.4 A) has been measured for the first time at 4 wavelengths near the M(V) edge using the beamline ID1 of ESRF (Grenoble, France). The present set up allowed to measure only 30% of the possible reflections at a resolution of 4 A, mainly because of the low sensitivity of the CCD detector. In the second experiment, the dispersion of the intensity of 5 X-ray diffraction peaks from pentakismethylammonium undecachlorodibismuthate (PMACB, orthorhombic unit cell; a = 13.003 A, b = 14.038 A, c = 15.450 A) has been measured at 30 wavelengths near the K absorption edge of chlorine (lambdaK = 4.397 A, EK= 2819.6 eV). All reflections within the resolution range from 6.4 A to 3.4 A expected in the 20 degree scan were observed. The chemical state varies between different chlorine atoms of PMACB, and so does the dispersion of different Bragg peaks near the K-edge of chlorine. The results reflect the performance of the beamline ID1 of ESRF at wavelengths beyond 3 A at the end of 1998. A gain by a factor 100 for diffraction experiments with 4.4 A photons was achieved in Autumn 1999 when two focusing mirrors had been added to the X-ray optics. Further progress is expected from area detectors more sensitive to soft X-rays. Both CCD detectors and image plates would provide a gain of two orders of measured intensity. Image plates would have the additional advantage that they can be bent cylindrically and thus cover a larger solid angle in reciprocal space. In many cases, samples need to be cooled: closed and open systems are presented. A comparison with the state of art of soft X-ray diffraction, as it had been reached at HASYLAB (Hamburg, Germany), and as it is developing at the Brookhaven National Laboratory (USA), is given. PMID:10976874

Carpentier, P; Berthet-Colominas, C; Capitan, M; Chesne, M L; Fanchon, E; Lequien, S; Stuhrmann, H; Thiaudière, D; Vicat, J; Zielinski, P; Kahn, R

2000-07-01

114

X-ray photoelectron spectroscopy and diffraction in the hard X-ray regime: Fundamental considerations and future possibilities  

Microsoft Academic Search

The prospects for extending X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD) measurements into the hard X-ray regime of 5–15keV excitation energies are discussed from a fundamental point of view, in some cases using prior results obtained in the 1–2keV range as starting points of discussion, together with theoretical estimates of behavior at higher energies. Subjects treated are: the

Charles S. Fadley

2005-01-01

115

X-ray photoelectron spectroscopy and diffraction in the hard X-ray regime: Fundamental considerations and future possibilities  

Microsoft Academic Search

The prospects for extending X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD) measurements into the hard X-ray regime of 5-15 keV excitation energies are discussed from a fundamental point of view, in some cases using prior results obtained in the 1-2 keV range as starting points of discussion, together with theoretical estimates of behavior at higher energies. Subjects treated

Charles S. Fadleya

116

X-ray photoelectron spectroscopy and diffraction in the hard X-ray regime: Fundamental considerations and future possibilities  

Microsoft Academic Search

The prospects for extending X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD) measurements into the hard X-ray regime of 5 15 keV excitation energies are discussed from a fundamental point of view, in some cases using prior results obtained in the 1 2 keV range as starting points of discussion, together with theoretical estimates of behavior at higher energies.

Charles S. Fadley

2005-01-01

117

X-ray photoelectron diffraction at high angular resolution  

Microsoft Academic Search

We present x-ray photoelectron diffraction (XPD) measurements at an angular resolution of ~+\\/-1.0° which is much higher than in any prior study. Emission from the Ni 2p3\\/2 core level of Ni(001) under Al Kalpha excitation is considered. The azimuthal XPD patterns are found to exhibit considerable fine structure not observed previously, including peaks whose full widths at half-maximum intensity are

J. Osterwalder; E. A. Stewart; D. Cyr; C. S. Fadley; J. Mustre de Leon; J. J. Rehr

1987-01-01

118

Multiple Scattering Effects on X-ray Photoelectron Diffraction  

Microsoft Academic Search

We describe the application of a full multiple-scattering cluster (MSC) method, known as the concentric-shell algorithm (CSA), for the simulation of X-ray photoelectron diffraction (XPD) data. By the use, within this scheme of a convenient approximation which exploits the strong forward scattering of electrons by atoms at such energies, we are able to perform XPD simulations at high kinetic energies

X. Chen; D. K. Saldin; T. Abukawa; S. Kono

1996-01-01

119

Low albite: an X-ray and neutron diffraction study  

Microsoft Academic Search

Least-squares refinements of the structure of low albite from Amelia, Virginia with three- dimensional neutron and X-ray diffraction intensity data sets yield weighted R factors of 0.024 and 0.035, respectively, with anisotropic thermal models. The two methods result in es- sentially identical positional parameters, though slight differences in thermal parameters may be due to the variation in relative scattering powers.

GBoncs E. HARLow

120

Nanoparticle Structure by Coherent X-ray Diffraction  

NASA Astrophysics Data System (ADS)

This review examines the physical reasons why nanoparticles differ in structure from the bulk. Certain simple properties of nanoparticles are explained through these structural differences. A powerful method of measuring the three dimensional structure of nanoparticles, Coherent X-ray diffraction (CXD), is introduced. A key experiment is described that uses CXD to study the redistribution of strains on the surface of a Au nanocrystal. Some future perspectives are discussed in conclusion.

Robinson, Ian

2013-02-01

121

Starch Gelatinization: An X-ray Diffraction Study  

Microsoft Academic Search

Cereal Chem. 65(6):443-446 Starch gelatinization was defined as the melting of starch crystallites, as granule fatty acids. Formation of these complexes partly explains determined by X-ray diffraction, in which the complete destruction of differences reported for heat of gelatinization values of amylose\\/lipid- crystallite integrity was observed as a function of moisture content and bearing starches because of competing melting and

H. F. ZOBEL; S. N. YOUNG; L. A. ROCCA

122

X-ray diffraction microscopy on frozen hydrated specimens  

NASA Astrophysics Data System (ADS)

X-rays are excellent for imaging thick samples at high resolution because of their large penetration depth compared to electrons and their short wavelength relative to visible light. To image biological material, the absorption contrast of soft X-rays, especially between the carbon and oxygen K-shell absorption edges, can be utilized to give high contrast, high resolution images without the need for stains or labels. Because of radiation damage and the desire for high resolution tomography, live cell imaging is not feasible. However, cells can be frozen in vitrified ice, which reduces the effect of radiation damage while maintaining their natural hydrated state. X-ray diffraction microscopy (XDM) is an imaging technique which eliminates the limitations imposed by current focusing optics simply by removing them entirely. Far-field coherent diffraction intensity patterns are collected on a pixelated detector allowing every scattered photon to be collected within the limits of the detector's efficiency and physical size. An iterative computer algorithm is then used to invert the diffraction intensity into a real space image with both absorption and phase information. This technique transfers the emphasis away from fabrication and alignment of optics, and towards data processing. We have used this method to image a pair of freeze-dried, immuno-labeled yeast cells to the highest resolution (13 nm) yet obtained for a whole eukaryotic cell. We discuss successes and challenges in working with frozen hydrated specimens and efforts aimed at high resolution imaging of vitrified eukaryotic cells in 3D.

Nelson, Johanna

123

Quantum-dot-array diffraction grating with single order diffraction property for soft x-ray region  

SciTech Connect

A gold transmission grating is used routinely to disperse the x-ray spectrum at the Z soft x-ray facility to measure the spectrum and temporal history of the absolute soft x-ray power emitted from z-pinch and hohlraum radiation sources. A quantum-dot-array diffraction grating (QDADG) of 250 lines/mm for soft x-ray is designed and fabricated for the first time according to the principle of binary sinusoidal transmission grating. The diffraction efficiencies of the grating are measured in the 150-300 eV photon energy range on the Beamline 3W1B of Beijing Synchrotron Radiation Facility. This article describes the basic concept and calibration techniques and presents calibration results. It is shown that the 250 lines/mm QDADG can be used to disperse light without higher-order diffractions in soft x-ray range, and the diffraction efficiencies of this grating are nearly constant (about 25%), which is beneficial in the spectrum analysis.

Kuang Longyu [Key Laboratory of Plasma Science and Technology, Research Center of Laser Fusion, China Academy of Engineering Physics, P.O. Box 919-986, Mianyang, Sichuan 621900 (China); Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230027 (China); Wang Chuanke; Wang Zhebin; Cao Leifeng; Liu Shenye; Ding Yongkun [Key Laboratory of Plasma Science and Technology, Research Center of Laser Fusion, China Academy of Engineering Physics, P.O. Box 919-986, Mianyang, Sichuan 621900 (China); Zhu Xiaoli; Xie Changqing [Key Laboratory of Nano-fabrication and Novel Devices Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China)

2010-07-15

124

X-ray nano-diffraction on cytoskeletal networks  

NASA Astrophysics Data System (ADS)

The nano-scale structure of cytoskeletal biopolymers as well as sophisticated superstructures determine the versatile cellular shapes and specific mechanical properties. One example is keratin intermediate filaments in epithelial cells, which form thick bundles that can further organize in a cross-linked network. To study the native structure of keratin bundles in whole cells, high-resolution techniques are required, which do at the same time achieve high penetration depths. We employ scanning x-ray diffraction using a nano-focused x-ray beam to study the structure of keratin in freeze-dried eukaryotic cells. By scanning the sample through the beam we obtain x-ray dark-field images with a resolution of the order of the beam size, which clearly show the keratin network. Each individual diffraction pattern is further analyzed to yield insight into the local sample structure, which allows us to determine the local structure orientation. Due to the small beam size we access the structure in a small sample volume without performing the ensemble average over one complete cell.

Weinhausen, Britta; Nolting, Jens-Friedrich; Olendrowitz, Christian; Langfahl-Klabes, Jannick; Reynolds, Michael; Salditt, Tim; Köster, Sarah

2012-08-01

125

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

NASA Astrophysics Data System (ADS)

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

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

1998-03-01

126

Synchrotron energy-dispersive X-ray diffraction tomography  

NASA Astrophysics Data System (ADS)

Energy-dispersive diffraction tomography using white-beam synchrotron X-rays with energies up to 140keV yields images of the interior features of solid objects up to 50mm thick. The volume sampled is determined by the geometry of the diffracting lozenge defined by the incident beam, the detector system collimation and the Bragg angle. Using conventional beam slits to form a highly collimated 50?mx50?m incident beam and a 40?m collimator aperture, we demonstrate on a PEEK phantom that a lateral resolution (transverse to the beam direction) of a few microns can be achieved. The resolution in the direction of the incident beam is necessarily poorer than this since the diffracting lozenge is elongated in this direction, with length increasing rapidly at small angles. There is no evidence of significant contamination of the diffracted intensity by the effects of multiple scattering from outside the primary lozenge.

Hall, C.; Barnes, P.; Cockcroft, J. K.; Colston, S. L.; Häusermann, D.; Jacques, S. D. M.; Jupe, A. C.; Kunz, M.

1998-04-01

127

Coherent X-ray diffractive imaging of protein crystals  

SciTech Connect

The technique of coherent X-ray diffraction imaging (CXDI) has recently shown great promise for the study of inorganic nanocrystals. In this work the CXDI method has been applied to the study of micrometer-size protein crystals. Finely sampled diffraction patterns of single crystals were measured and iterative phase-retrieval algorithms were used to reconstruct the two-dimensional shape of the crystal. The density maps have limited reproducibility because of radiation damage, but show clear evidence for crystal facets. Qualitative analysis of a number of single-crystal diffraction peaks indicates the presence of inward surface contraction on 2 {micro}m size crystals. A survey of several hundred diffraction patterns yielded a number of examples with dramatic single-sided streaks, for which a plausible model is constructed.

Boutet, Sebastien; Robinson, Ian K. (UIUC)

2009-09-25

128

Fabrication, measurement, and analysis of multilayer x- ray diffraction gratings  

NASA Astrophysics Data System (ADS)

I examine the theory and fabrication of lamellar multilayer x-ray diffraction gratings. I use current theory based on the Kirchoff Integral for amplitude gratings and a new equation for phase gratings to analyze current technology multilayer grating performance (where the period/? exceeds 10). I examine the possible fabrication methods and define two general categories (additive: multilayer added to patterned substrate, subtractive: grating etched into multilayer). I conclude the additive approach is superior, leading to x-ray analogues to binary optics and holographic optical elements. I define an additive process in detail and demonstrate the serviceability of the key processes: thermal growth of silicon dioxide on silicon, lithography, a combined plasma-etch and wet-etch. Multilayer fabrication difficulties on patterned substrates are identified, including: mushroom cap growth, and filleting in the grooves. Measurements done at NSLS on 2 amplitude gratings and 1 phase grating are reported. The data is shown to be compatible with the Kirchoff theory.

Hansen, Douglas P.

1997-12-01

129

Diffraction imaging of crystals with focused x-ray beams  

SciTech Connect

We describe an imaging technique based on diffraction of a focused x-ray beam in crystals. A focused beam is formed by a zone plate and Bragg diffracted from a crystalline sample positioned between the zone plate and the focus. The intensity pattern is recorded by a high-resolution charge-coupled-device detector placed in the focus. Diffraction images recorded from perfect Si and GaAs crystals for various reflections demonstrate the broadening of the focused beam due to a finite scattering length. The images from semiconductor epitaxial films and heterostructures show additional peaks originating from the interfaces with their spatial position corresponding to the depth from the surface. Diffraction images from isolated defects in Si crystal demonstrate capabilities to study bulk defects. Theoretical simulations for perfect crystals show excellent agreement with experiments. We demonstrate that the new imaging technique is depth sensitive and combines structural sensitivity of traditional x-ray topography methods with spatial in-plane resolution provided by focusing.

Kazimirov, A. [CHESS, Cornell University, Ithaca, New York 14853 (United States); Kohn, V. G. [Russian Research Center 'Kurchatov Institute', 123182 Moscow (Russian Federation); Cai, Z.-H. [Advanced Photon Source, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States)

2010-06-01

130

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

PubMed

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

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

2012-01-01

131

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

PubMed Central

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

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

2012-01-01

132

Fabrication of Diffraction Grating with High Aspect Ratio Using X-ray Lithography Technique for X-ray Phase Imaging  

Microsoft Academic Search

The use of conventional X-ray radiography is limited due to weak absorption. This problem is resolved by using phase-sensitive imaging methods to improve the contrast, such as X-ray Talbot interferometry. With a spatially coherent light source and two diffraction gratings for Talbot interferometry, we measured the phase change differential. Using this technique, diffraction gratings were designed to have a fine

Daiji Noda; Makoto Tanaka; Kazuma Shimada; Tadashi Hattori

2007-01-01

133

Theoretical and experimental study of soft X-ray diffraction by a lamellar multilayer amplitude grating  

Microsoft Academic Search

The authors give a theoretical and experimental study of soft X-ray diffraction by a lamellar multilayer amplitude grating. Absolute efficiency measurements are obtained at 277 eV with a 1000 lines\\/mm grating etched in a Mo\\/C multilayer structure and comments based on numerical simulations performed in the framework of a dynamical theory of diffraction are presented. Effects which are not accounted

A. Sammar; M. Ouahabi; R. Barchewitz; J.-M. Andre; R. Rivoira; C. Khan Malek; F. R. Ladan; P. Guerin

1993-01-01

134

X-ray lensless microscopy from undersampled diffraction intensities  

NASA Astrophysics Data System (ADS)

X-ray coherent diffraction imaging including ptychography provides the nanoscale resolved three-dimensional description of matter. The combination of these approaches to the Bragg geometry case arouses a strong interest for its capability to provide information about strain state in crystals. Among the existing approaches, ptychography is particularly appealing because it allows the investigation of extended or weakly scattering samples. Coherent diffraction imaging approaches, based on redundancy in the collected diffraction intensity data set, are highly time consuming and rely on state-of-the-art mechanical setups, both being strong limitations for a general application. We show here that these can be overcome by regularization-based inversion algorithms introducing a priori structural knowledge. This method, which can be generalized to other wavelengths or beam sources, opens new possibilities for the imaging of radiation-sensitive specimens or very large samples.

Berenguer, F.; Godard, P.; Allain, M.; Belloir, J.-M.; Talneau, A.; Ravy, S.; Chamard, V.

2013-10-01

135

High Pressure X-ray Diffraction Study of Potassium Azide  

SciTech Connect

Crystal structure and compressibility of potassium azide was investigated by in-situ synchrotron powder X-ray diffraction in a diamond anvil cell at room temperature up to 37.7 GPa. In the body-centered tetragonal (bct) phase, an anisotropic compressibility was observed with greater compressibility in the direction perpendicular to the plane containing N{sub 3}{sup -} ions than directions within that plane. The bulk modulus of the bct phase was determined to be 18.6(7) GPa. A pressure-induced phase transition may occur at 15.5 GPa.

C Ji; F Zhang; D Hong; H Zhu; J Wu; M Chyu; V Levitas; Y Ma

2011-12-31

136

Geometry and X-ray diffraction characteristics of carbon nanotubes  

SciTech Connect

Algorithms for generating atomic coordinates in nanotubes with an arbitrary cell in the layer plane have been developed. The conditions for the seamless matching of a flat layer rolled up in any direction are formulated for cylindrical, conical, and faceted tubes. A method has been developed for generating different types of faceted nanotubes using a group transformation (obtained in this study) that leaves invariant an arbitrary polygon in the nanotube cross section. Equations are proposed for deriving the diameter and chirality of single-wall carbon cylindrical nanotubes from X-ray diffraction spectra.

Pleshakov, V. F., E-mail: victorpleshakov@list.ru [FGUP Scientific Research Institute of Electrical Carbon Products (Russian Federation)

2009-12-15

137

Counting dislocations in microcrystals by coherent x-ray diffraction.  

PubMed

We present here an unprecedented way of quantifying the number of dislocations in microcrystals. This method relies on a combination of several state-of-the-art techniques: coherent x-ray diffraction used as a local probe, together with the controlled compression of micro-objects. We demonstrate that by using this method, dislocations in the microcrystal can be detected and their number precisely quantified. This cannot be done with other techniques in a nondestructive way. Our method opens a route for the study of many small-scale systems with defect-dependent physical properties and it could become a critical tool for addressing future challenges in nanotechnology. PMID:23971584

Jacques, V L R; Carbone, D; Ghisleni, R; Thilly, L

2013-08-07

138

Determination of absolute chirality using resonant X-ray diffraction  

NASA Astrophysics Data System (ADS)

We have demonstrated that resonant diffraction experiments using the circularly polarized X-ray beam absolutely determines the crystal chirality. Both berlinite and quartz crystals belonging to space group P3221 show higher azimuth-constant intensity for the negative (-) helicity beam than that for the the positive (+) helicity beam for space-group forbidden reflection 001. The relation is opposite for quartz crystal belonging to space group P3121. Theoretical calculation shows that this relation completely agrees with the experimental findings for the enantiomorphic space-group pair P3121 and P3221. This method is applicable to chiral motifs that occur in biomolecules, liquid crystals, ferroelectrics, and multiferroics, etc.

Tanaka, Y.; Lovesey, S. W.

2012-06-01

139

Counting Dislocations in Microcrystals by Coherent X-Ray Diffraction  

NASA Astrophysics Data System (ADS)

We present here an unprecedented way of quantifying the number of dislocations in microcrystals. This method relies on a combination of several state-of-the-art techniques: coherent x-ray diffraction used as a local probe, together with the controlled compression of micro-objects. We demonstrate that by using this method, dislocations in the microcrystal can be detected and their number precisely quantified. This cannot be done with other techniques in a nondestructive way. Our method opens a route for the study of many small-scale systems with defect-dependent physical properties and it could become a critical tool for addressing future challenges in nanotechnology.

Jacques, V. L. R.; Carbone, D.; Ghisleni, R.; Thilly, L.

2013-08-01

140

Anomalous X-ray Diffraction Studies for Photovoltaic Applications  

SciTech Connect

Anomalous X-ray Diffraction (AXRD) has become a useful technique in characterizing bulk and nanomaterials as it provides specific information about the crystal structure of materials. In this project we present the results of AXRD applied to materials for photovoltaic applications: ZnO loaded with Ga and ZnCo{sub 2}O{sub 4} spinel. The X-ray diffraction data collected for various energies were plotted in Origin software. The peaks were fitted using different functions including Pseudo Voigt, Gaussian, and Lorentzian. This fitting provided the integrated intensity data (peaks area values), which when plotted as a function of X-ray energies determined the material structure. For the first analyzed sample, Ga was not incorporated into the ZnO crystal structure. For the ZnCo{sub 2}O{sub 4} spinel Co was found in one or both tetrahedral and octahedral sites. The use of anomalous X-ray diffraction (AXRD) provides element and site specific information for the crystal structure of a material. This technique lets us correlate the structure to the electronic properties of the materials as it allows us to probe precise locations of cations in the spinel structure. What makes it possible is that in AXRD the diffraction pattern is measured at a number of energies near an X-ray absorption edge of an element of interest. The atomic scattering strength of an element varies near its absorption edge and hence the total intensity of the diffraction peak changes by changing the X-ray energy. Thus AXRD provides element specific structural information. This method can be applied to both crystalline and liquid materials. One of the advantages of AXRD in crystallography experiments is its sensitivity to neighboring elements in the periodic tables. This method is also sensitive to specific crystallographic phases and to a specific site in a phase. The main use of AXRD in this study is for transparent conductors (TCs) analysis. TCs are considered to be important materials because of their efficiency and low risk of environmental pollution. These materials are important to solar cells as a result of their remarkable combination of optical and electrical properties, including high electrical conductivity and high optical transparency in the spectrum of visible light. TCs provide a transparent window, which allows sunlight to pass through while also allowing electricity to conduct out of the cell. Spinel materials have the chemical form AB{sub 2}O{sub 4}, and are made of a face-centered cubic (FCC) lattice of oxygen anions and cations in specific interstitial sites. A normal spinel has all A cations on tetrahedral sites and B cations on octahedral sites. In contrast; an inverse spinel has the A and half of the B cations on octahedral sites and the other half of the B cations on tetrahedral sites; a mixed spinel lies between. In the spinel structure, 8 of 64 possible tetrahedral sites and 16 of 32 possible octahedral sites are filled. Normal spinels have particularly high conduction as the linear octahedral chains of B cations likely serve as conduction paths. In this paper we present how the data obtained with AXRD is used to analyze TCs properties as they apply to photovoltaic applications. One of the materials used for this analysis is zinc oxide. It has been loaded with 5% and 10% of Ga, which has an absorption edge of 10367 eV. The peak (100) was measured for the zinc oxide loaded with 10% Ga. In the case of 5% Ga, we measured peaks (100) and (101). With the information provided by the AXRD we can identify if Ga is being incorporated in the ZnO crystal structure. The analysis of 311 plane in the ZnCo{sub 2}O{sub 4} spinel shows if Co is in tetrahedral or octahedral site.

Not Available

2011-06-22

141

DiffractX: A Simulation Toolbox for Diffractive X-ray Optics  

NASA Astrophysics Data System (ADS)

X-ray wavefront propagation is a powerful technique when simulating the performance of x-ray optical components. Using various numerical methods, interesting parameters such as focusing capability and efficiency can be investigated. Here we present the toolbox DiffractX, implemented in MATLAB. It contains many different wave propagation methods for the simulation of diffractive x-ray optics, including Fresnel propagation, the finite difference method (FDM), the thin object approximation, the rigorous coupled wave theory (RCWT), and the finite element method (FEM). All tools are accessed through a graphical interface, making the design of simulations fast and intuitive, even for users with little or no programming experience. The tools have been utilized to characterize realistic as well as idealized optical components. This will aid further developments of diffractive x-ray optics.

Selin, M.; Bertilson, M.; Nilsson, D.; von Hofsten, O.; Hertz, H. M.; Vogt, U.

2011-09-01

142

Ultrafast molecular processes mapped by femtosecond x-ray diffraction  

NASA Astrophysics Data System (ADS)

X-ray diffraction with a femtosecond time resolution allows for mapping photoinduced structural dynamics on the length scale of a chemical bond and in the time domain of atomic and molecular motion. In a pump-probe approach, a femtosecond excitation pulse induces structural changes which are probed by diffracting a femtosecond hard x-ray pulse from the excited sample. The transient angular positions and intensities of diffraction peaks give insight into the momentary atomic or molecular positions and into the distribution of electronic charge density. The simultaneous measurement of changes on different diffraction peaks is essential for determining atom positions and charge density maps with high accuracy. Recent progress in the generation of ultrashort hard x-ray pulses (Cu K?, wavelength ?=0.154 nm) in laser-driven plasma sources has led to the implementation of the powder diffraction and the rotating crystal method with a time resolution of 100 fs. In this contribution, we report new results from powder diffraction studies of molecular materials. A first series of experiments gives evidence of a so far unknown concerted transfer of electrons and protons in ammonium sulfate [(NH4)2SO4], a centrosymmetric structure. Charge transfer from the sulfate groups results in the sub-100 fs generation of a confined electron channel along the c-axis of the unit cell which is stabilized by transferring protons from the adjacent ammonium groups into the channel. Time-dependent charge density maps display a periodic modulation of the channel's charge density by low-frequency lattice motions with a concerted electron and proton motion between the channel and the initial proton binding site. A second study addresses atomic rearrangements and charge dislocations in the non-centrosymmetric potassium dihydrogen phosphate [KH2PO4, KDP]. Photoexcitation generates coherent low-frequency motions along the LO and TO phonon coordinates, leaving the average atomic positions unchanged. The time-dependent maps of electron density demonstrate a concomitant oscillatory relocation of electronic charge with a spatial amplitude of the order of a chemical bond length, two orders of magnitude larger than the vibrational amplitudes. The coherent phonon motions drive the charge relocation, similar to a soft mode driven phase transition between the ferro- and paraelectric phase of KDP.

Elsaesser, Thomas

2012-02-01

143

Beam line for experiments with coherent soft x-rays  

SciTech Connect

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

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

1982-12-01

144

Simple X-ray cameras for beam-line instrumentation  

NASA Astrophysics Data System (ADS)

The design and performance characterization of simple X-ray cameras are shortly presented. These cameras are installed on each high-energy beam-lines of SOLEIL. Main topics, such as the choice of the scintillator, the effect of the thickness of the scintillator on the resolution, the relation between the X-ray flux and the signal, are addressed in this article.

Bordessoule, M.

2013-03-01

145

X-ray Diffraction Studies of Striated Muscles  

SciTech Connect

In this short review a number of recent X-ray diffraction results on the highly ordered striated muscles in insects and in bony fish have been briefly described. What is clear is that this technique applied to muscles which are amenable to rigorous analysis, taken together with related data from other sources (e.g. protein crystallography, biochemistry, mechanics, computer modelling) can provide not only the best descriptions yet available on the myosin head organisations on different myosin filaments in the relaxed state, but can also show the sequence of molecular events that occurs in the contractile cycle, and may also help to explain such phenomena as stretch-activation. X-ray diffraction is clearly an enormously powerful tool in studies of muscle. It has already provided a wealth of detail on muscle ultrastructure; it is providing ever more fascinating insights into molecular events in the 50-year old sliding filament mechanism, and there remains a great deal more potential that is as yet untapped.

Squire, J.M.; Knupp, C.; Roessle, M.; Al-Khayat, H.A.; Irving, T.C.; Eakins, F.; Mok, N.-S.; Harford, J.J.; Reedy, M.K. (IIT); (Duke); (ESRF); (ICL)

2006-04-24

146

New HMI hard X-ray Diffraction Beamlines at BESSY  

NASA Astrophysics Data System (ADS)

Since April 2005 the Hahn-Meitner-Institute is operating two new beamlines for energy dispersive diffraction experiments (EDDI) and for (resonant) magnetic scattering (MAGS) at BESSY. The source for both beamlines is a superconducting 7 T multipole wiggler which provides hard X-ray photons with energies between 4 and 150 keV. The EDDI beamline uses the white beam and is intended for residual stress measurements on small samples as well as heavy engineering parts. The MAGS beamline delivers a focussed monochromatic beam with photon fluxes in the 1012 (s 100 mA 0.1 % bandwidth)-1 range at energies from 4 to 30 keV. It is equipped for single crystal diffraction and resonant (magnetic) scattering experiments as well as for the study of thin films, micro-, and nanostructures in materials science.

Denks, I. A.; Genzel, C.; Dudzik, E.; Feyerherm, R.; Klaus, M.; Wagener, G.

2007-01-01

147

Diffraction and holography of photoelectrons and fluorescent x-rays  

SciTech Connect

Photoelectron diffraction is by now a powerful technique for studying surface structures, with special capabilities for resolving chemical and magnetic states of atoms and deriving direct structural information from both forward scattering and backscattering. Fitting experiment to theory can lead to structural accuracies in the 0.03 {Angstrom} range. Holographic inversions of such diffraction data also show considerable promise for deriving local three-dimensional structures around a given emitter with accuracies of 0.2--0.3 {Angstrom}. Resolving the photoelectron spin in some way and using circularly polarized radiation for excitation provide added dimensions for the study of magnetic systems and chiral experimental geometries. Synchrotron radiation with the highest brightness and energy resolution, as well as variable polarization, is crucial to the full exploitation of these techniques. X-ray fluorescence holography also has promise for structural studies, but will require intense excitation sources and multichannel detection to be feasible.

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

1993-04-01

148

Diffractive-refractive optics: X-ray splitter.  

PubMed

The possibility of splitting a thin (e.g. undulator) X-ray beam based on diffraction-refraction effects is discussed. The beam is diffracted from a crystal whose diffracting surface has the shape of a roof with the ridge lying in the plane of diffraction. The crystal is cut asymmetrically. One half of the beam impinges on the left-hand part of the roof and the other half impinges on the right-hand side of the roof. Owing to refraction the left part of the beam is deviated to the left whereas the right part is deviated to the right. The device proposed consists of two channel-cut crystals with roof-like diffraction surfaces; the crystals are set in a dispersive position. The separation of the beams after splitting is calculated at a distance of 10 m from the crystals for various asymmetry and inclination angles. It is shown that such a splitting may be utilized for long beamlines. Advantages and disadvantages of this method are discussed. PMID:20029121

Hrdý, Jaromír

2009-11-17

149

Dynamical x-ray diffraction from nonuniform crystalline films: Application to x-ray rocking curve analysis  

Microsoft Academic Search

A dynamical model for the general case of Bragg x-ray diffraction from arbitrarily thick nonuniform crystalline films is presented. The model incorporates depth-dependent strain and a spherically symmetric Gaussian distribution of randomly displaced atoms and can be applied to the rocking curve analysis of ion-damaged single crystals and strained layer superlattices. The analysis of x-ray rocking curves using this model

C. R. Wie; T. A. Tombrello; T. Vreeland Jr.

1986-01-01

150

X-ray diffraction spectroscopy and X-ray photoelectron spectroscopy studies of Cu-doped ZnO films  

Microsoft Academic Search

Cu-doped ZnO films have been prepared using direct current co-reactive magnetron sputtering technique at different oxygen partial pressures. The microstructure and the chemical state of oxygen, copper and zinc in ZnO films was investigated by X-ray diffraction spectroscopy (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The results indicate that ZnO films with moderate Cu doping can obtain wurtzite structure with

H. Xue; Y. Chen; X. L. Xu; G. H. Zhang; H. Zhang; S. Y. Ma

2009-01-01

151

Synchrotron X-ray Powder Diffraction and Absorption Spectroscopy in Pulsed Magnetic Fields with Milliseconds Duration  

SciTech Connect

X-ray Powder Diffraction and X-ray Absorption Spectroscopy experiments (WAS) and X-ray magnetic circular dichroism (XMCD) experiments were carried out at the ESRF DUBBLE beam line (BM26) and at the energy dispersive beam line (ID24), respectively. A mobile pulse generator, developed at the LNCMP, delivered 110kJ to the load coil, which was sufficient to generate peak fields of 30T with a rise time of about 5 ms. A liquid He flow cryostat allowed us to vary the sample temperature accurately between 4.2K and 300K.Powder diffraction patterns of TbVO4 were recorded in a broad temperature range using 21 keV monochromatic X-rays and using an on-line image plate detector. We observed the suppression of the Jahn-Teller structural distortion in TbVO4 due to the high magnetic pulsed field.XAS spectra could be measured and finite XMCD signals, directly proportional to the magnetic moment on the Gd absorber atom, were measured in thin Gd foils. Thanks to its element and orbital selectivity, XMCD proofs to be very useful in probing the magnetic properties and due to the strong brilliance of the synchrotron beam, the signals can be measured even in the ms range.

Vanacken, J. [LNCMP, 143, avenue de Rangueil BP 14245, F31432 Toulouse (France); Pulsveldengroep, INPAC, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Detlefs, C.; Mathon, O.; Dominguez, M.-C. [ESRF, BP 220, F-38043 Grenoble (France); Frings, P.; Duc, F.; Nardone, M.; Billette, J.; Zitouni, A.; Rikken, G. [LNCMP, 143, avenue de Rangueil BP 14245, F31432 Toulouse (France); Lorenzo, J. E. [Laboratoire de Cristallographie, CNRS, B.P.166X, F-38043 Grenoble (France); Herczeg, J.; Moshchalkov, V. V. [Pulsveldengroep, INPAC, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Bras, W. [DUBBLE CRG at ESRF, BP 220, F-38043 Grenoble (France)

2007-03-30

152

Synchrotron X-ray Powder Diffraction and Absorption Spectroscopy in Pulsed Magnetic Fields with Milliseconds Duration  

NASA Astrophysics Data System (ADS)

X-ray Powder Diffraction and X-ray Absorption Spectroscopy experiments (WAS) and X-ray magnetic circular dichroism (XMCD) experiments were carried out at the ESRF DUBBLE beam line (BM26) and at the energy dispersive beam line (ID24), respectively. A mobile pulse generator, developed at the LNCMP, delivered 110kJ to the load coil, which was sufficient to generate peak fields of 30T with a rise time of about 5 ms. A liquid He flow cryostat allowed us to vary the sample temperature accurately between 4.2K and 300K. Powder diffraction patterns of TbVO4 were recorded in a broad temperature range using 21 keV monochromatic X-rays and using an on-line image plate detector. We observed the suppression of the Jahn-Teller structural distortion in TbVO4 due to the high magnetic pulsed field. XAS spectra could be measured and finite XMCD signals, directly proportional to the magnetic moment on the Gd absorber atom, were measured in thin Gd foils. Thanks to its element and orbital selectivity, XMCD proofs to be very useful in probing the magnetic properties and due to the strong brilliance of the synchrotron beam, the signals can be measured even in the ms range.

Vanacken, J.; Detlefs, C.; Mathon, O.; Frings, P.; Duc, F.; Lorenzo, J. E.; Nardone, M.; Billette, J.; Zitouni, A.; Dominguez, M.-C.; Herczeg, J.; Bras, W.; Moshchalkov, V. V.; Rikken, G.

2007-03-01

153

Applications of parametric X-rays for X-ray diffraction analysis  

Microsoft Academic Search

Until now parametric X-rays (PXR) have not had practical applications because of the lack of a modern compact accelerator providing the required beam current and consequently high X-ray photon flux. PXR sources even with the intensities achievable at present may be applied to a number of X-ray reflectometry and diffractometry measurements which are important for the characterization of crystals and

I. D. Feranchuk; A. S. Lobko

2008-01-01

154

Experimental Qualification of a Novel X-Ray Diffraction Imaging Setup Based on Polycapillary X-Ray Optics  

Microsoft Academic Search

X-ray Diffraction Imaging is a technique able to highlight the differences in the molecular composition of the sample under analysis owing to the difference in their scattering properties. A laboratory based imaging system that will allow well-resolved diffraction images in space and energy was designed, setup and experimentally qualified. The key features of the proposed system are the following: (i)

A. Castoldi; C. Ozkan; C. Guazzoni; A. Bjeoumikhov; R. Hartmann

2010-01-01

155

Fabrication of large area X-ray diffraction grating for X-ray phase imaging  

SciTech Connect

X-ray lithography, which uses highly directional synchrotron radiation, is one of the technologies that can be used for fabricating micrometer-sized structures. In X-ray lithography, the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Since X-ray radiation is highly directional, a micro-fabrication technology that produces un-tapered and high aspect ratio highly absorbent structures on a low absorbent membrane is required. Conventionally, a resin material is used as the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. Therefore, we proposed and used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. We fabricated new carbon membrane X-ray masks, and these results of X-ray lithography demonstrate the superior performance.

Noda, Daiji; Tokuoka, Atsushi; Katori, Megumi; Minamiyama, Yasuto; Yamashita, Kenji; Nishida, Satoshi; Hattori, Tadashi [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Koto, Kamigori, Ako, Hyogo 678-1205 (Japan); Nanocreate Co., Ltd, 9-8-6 Tsujii, Himeji, Hyogo 670-0083 (Japan)

2012-07-31

156

Fabrication of large area X-ray diffraction grating for X-ray phase imaging  

NASA Astrophysics Data System (ADS)

X-ray lithography, which uses highly directional synchrotron radiation, is one of the technologies that can be used for fabricating micrometer-sized structures. In X-ray lithography, the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Since X-ray radiation is highly directional, a micro-fabrication technology that produces un-tapered and high aspect ratio highly absorbent structures on a low absorbent membrane is required. Conventionally, a resin material is used as the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. Therefore, we proposed and used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. We fabricated new carbon membrane X-ray masks, and these results of X-ray lithography demonstrate the superior performance.

Noda, Daiji; Tokuoka, Atsushi; Katori, Megumi; Minamiyama, Yasuto; Yamashita, Kenji; Nishida, Satoshi; Hattori, Tadashi

2012-07-01

157

X-ray Diffraction Spectra in Cu-Implanted SiO{sub 2} Films on Si(100) Substrates  

SciTech Connect

Cu-implanted SiO{sub 2} films on Si(100) have been studied using x-ray methods and x-ray diffraction pattern processing. The x-ray results indicate the presence of a preferred orientation for Cu {l_brace}111{r_brace} planes parallel to the substrate surface without directional orientation for Cu-implanted SiO{sub 2}/Si(100) and nano-crystalline-Cu/SiO{sub 2}/Si(100)(ie. after implanted and annealed Cu). The x-ray diffraction spectra of the Cu-implanted and nano-crystalline-Cu phases were analyzed (ie. in terms of peak search, profile fit, crystallite size) and compared to data from complimentary techniques (RBS, TEM). Results are discussed with respect to x-ray spectral lines shapes derived from XRD spectra processing and the nanostructure problem.

Shirokoff, J. [Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3X5 (Canada); Lewis, J. Courtenay [Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3X7 (Canada)

2010-10-29

158

Biological imaging by soft X-ray diffraction microscopy  

NASA Astrophysics Data System (ADS)

We have developed a microscope for soft x-ray diffraction imaging of dry or frozen hydrated biological specimens. This lensless imaging system does not suffer from the resolution or specimen thickness limitations that other short wavelength microscopes experience. The microscope, currently situated at beamline 9.0.1 of the Advanced Light Source, can collect diffraction data to 12 nm resolution with 750 eV photons and 17 nm resolution with 520 eV photons. The specimen can be rotated with a precision goniometer through an angle of 160 degrees allowing for the collection of nearly complete three-dimensional diffraction data. The microscope is fully computer controlled through a graphical user interface and a scripting language automates the collection of both two-dimensional and three-dimensional data. Diffraction data from a freeze-dried dwarf yeast cell, Saccharomyces cerevisiae carrying the CLN3-1 mutation, was collected to 12 run resolution from 8 specimen orientations spanning a total rotation of 8 degrees. The diffraction data was phased using the difference map algorithm and the reconstructions provide real space images of the cell to 30 nm resolution from each of the orientations. The agreement of the different reconstructions provides confidence in the recovered, and previously unknown, structure and indicates the three dimensionality of the cell. This work represents the first imaging of the natural complex refractive contrast from a whole unstained cell by the diffraction microscopy method and has achieved a resolution superior to lens based x-ray tomographic reconstructions of similar specimens. Studies of the effects of exposure to large radiation doses were also carried out. It was determined that the freeze-dried cell suffers from an initial collapse, which is followed by a uniform, but slow, shrinkage. This structural damage to the cell is not accompanied by a diminished ability to see small features in the specimen. Preliminary measurements on frozen-hydrated yeast indicate that the frozen specimens do not exhibit these changes even with doses as high as 5 x 109 Gray.

Shapiro, David

159

(Diffraction gratings used in x-ray spectroscopy): Final report  

SciTech Connect

This subcontract was initiated in order to facilitate the development at MIT of technologies for fabricating the very fine diffraction grating required in x-ray spectroscopy at Lawrence Livermore Laboratory (LLL). These gratings are generally gold transmission gratings with spatial periods of 200 nm or less. The major focus of our efforts was to develop a means of fabricating gratings of 100 nm period. We explored two approaches: e-beam fabrication of x-ray lithography masks, and achromatic holographic lithography. This work was pursued by Erik Anderson as a major component of his Ph.D. thesis. Erik was successful in both the e-beam and holographic approaches. However, the e-beam method proved to be highly impractical: exposure times of about 115 days would be required to cover an area of 1 cm/sup 2/. The achromatic holography, on the other hand, should be capable of exposing areas well in excess of 1 cm/sup 2/ in times under 1 hour. Moreover, 100 nm-period gratings produced by achromatic holography are coherent over their entire area whereas gratings produced by e-beam lithography are coherent only over areas /approximately/100 ..mu..m. The remainder of this report consists of portions excerpted from Erik Anderson's thesis. These contain all the details of our work on 100 nm period gratings. 26 refs., 17 figs.

Smith, H.I.

1988-11-01

160

Development of Coherent X-ray Diffraction Apparatus with Kirkpatrick-Baez Mirror Optics  

NASA Astrophysics Data System (ADS)

To realize coherent x-ray diffraction microscopy with higher spatial resolution, it is necessary to increase the density of x-ray photons illuminated onto the sample. In this study, we developed a coherent x-ray diffraction apparatus with Kirkpatrick-Baez mirror optics. By using mirrors fabricated by elastic emission machining, a high-density coherent x-ray beam was produced. In a demonstration experiment using a silver nanocube as a sample, a high-contrast coherent x-ray diffraction pattern was observed over a wide-q range. This proves that both the density and the degree of coherence of the focused beam were high.

Takahashi, Y.; Tsutsumi, R.; Nishino, Y.; Mimura, H.; Matsuyama, S.; Ishikawa, T.; Yamauchi, K.

2011-09-01

161

Development of Coherent X-ray Diffraction Apparatus with Kirkpatrick-Baez Mirror Optics  

SciTech Connect

To realize coherent x-ray diffraction microscopy with higher spatial resolution, it is necessary to increase the density of x-ray photons illuminated onto the sample. In this study, we developed a coherent x-ray diffraction apparatus with Kirkpatrick-Baez mirror optics. By using mirrors fabricated by elastic emission machining, a high-density coherent x-ray beam was produced. In a demonstration experiment using a silver nanocube as a sample, a high-contrast coherent x-ray diffraction pattern was observed over a wide-q range. This proves that both the density and the degree of coherence of the focused beam were high.

Takahashi, Y. [Frontier Research Base for Global Young Researchers, Frontier Research Center, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Tsutsumi, R.; Mimura, H.; Matsuyama, S. [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishino, Y. [Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021 (Japan); Ishikawa, T. [RIKEN SPring-8 Center, Kouto, Sayo, Sayo, Hyogo 679-5148 (Japan); Yamauchi, K. [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Research Center for Ultra-precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

2011-09-09

162

Time-Resolved X-ray Diffraction Station: X-ray Optics, Detectors and Data Acquisition,  

National Technical Information Service (NTIS)

A new x-ray beamline has recently been built, and is now operational, on dipole magnet 2 of the Synchrotron Radiation Source (SRS) at Daresbury. This beamline takes 32 mrad of horizontal aperture from a center tangent point. The Time Resolved X-ray Diffra...

E. Towns-Andrews A. Berry J. Bordas G. R. Mant P. K. Murray

1988-01-01

163

CCMR: X-Ray Diffraction of Magnetic Tunnel Junctions  

NSDL National Science Digital Library

We examined CoFeB/MgO/CoFeB magnetic tunnel junctions with X-ray diffraction in order to determine the effects of anneal temperature, MgO growth type, and seed layer structure on electrode and tunnelbarrier crystallinity. For various sample structures and growth methods, we show electrode crystallinity and texturing improving with increasing anneal temperature, while MgO texturing peaks between 350 C and 400 C. We find the amount and texturing of electrode and barrier crystallinity varies widely with the MgO growth method, with electrode crystallization greatest in samples with MgO grown using ebeam evaporation. Finally, we report that for our sample structures, Ta/CuN seed layers promote the highest level of CoFeB electrode texturing.

Huang, Pinshane Y.

2007-08-29

164

Preparation and X-ray diffraction studies of curium hydrides  

NASA Astrophysics Data System (ADS)

Curium hydrides were prepared by reaction of curium-248 metal with hydrogen and characterized by X-ray powder diffraction. Several of the syntheses resulted in a hexagonal compound with average lattice parameters of a0 = 0.3769(8) nm and c0 = 0.6732(12) nm. These products are considered to be CmH3-? by analogy with the behavior of lanthanide-hydrogen and lighter actinide-hydrogen systems. Face-centered cubic products with an average lattice parameter of a0 = 0.5322(4) nm were obtained from other curium hydride preparations. This parameter is slightly smaller than that reported previously for cubic curium dihydride, CmH2+x (B. M. Bansal and D. Damien, Inorg. Nucl. Chem. Lett., 6, 603, 1970). The present results established a continuation of typical heavy trivalent lanthanide-like behavior of the transuranium actinide-hydrogen systems through curium.

Gibson, J. K.; Haire, R. G.

1985-10-01

165

Special properties of X-ray diffraction on carbon onions  

SciTech Connect

The kinematic theory of X-ray diffraction was applied to the study of the most intense Bragg's reflection observed for carbon onions. It was shown that the agreement with experimental data was attained using a convolution of a Lorentzian contour with regard to the distribution of onion sizes and of an asymmetric contour taking into account the fluctuations of intershell distances inside the particle. It can be assumed that the observed scatter in intershell distances indicates a nonequilibrium state of the internal configuration of onion shells. It appeared to be possible to estimate not only the average onion size, which exceeds the average size of pristine nanodiamonds that are used for onion preparation by annealing, but their size distribution function as well.

Yastrebov, S. G., E-mail: yastrebov@mail.ioffe.ru; Ivanov-Omskii, V. I. [Russian Academy of Sciences, Ioffe Physicotechnical Instutute (Russian Federation)

2007-12-15

166

Nondestructive evaluation of fatigue damage in aluminum 2024 by x-ray diffraction  

NASA Astrophysics Data System (ADS)

Aluminum alloys are widely used in the automobile and aerospace industries. This is due to their attractive low density-high modulus and low density-high strength characteristics. Unfortunately, cyclic stress-strain deformations alter the microstructure of aluminum alloys when they are placed into service. These structural changes can lead to fatigue damage and ultimately service failure. Since x-ray diffraction analysis is known to be a sensitive nondestructive indicator of structural changes due to deformations, this technique is being used to evaluate changes in the microstructure of cycled aluminum 2024 commercial alloys. Line shapes, widths, and positions in an x-ray diffraction pattern depend on microstructural properties such as grain size, grain orientation, residual stress, microstrain, etc. Changes in the microstructure due to fatigue will appear as changes in the diffraction pattern. One parameter used to characterize a reflection in a diffraction pattern is the full width at half maximum (FWHM). Preliminary x-ray diffraction results on cycled Al 2024 indicate that the (111) and (222) reflections of the matrix phase do not show any variations in the FWHM due to an increase in the fatigue cycles. However, the FWHM of the (200) and (400) reflections of the same phase unexpectedly showed a dramatic decrease. These results can be interpreted as due to the relaxation of some initial nonuniform residual stresses in the matrix phase lattice. Further work is in progress to evaluate the FWHM of the second phase of the cycled alloys.

Ferguson, Milton W.

1994-12-01

167

Elimination of higher-order diffraction using zigzag transmission grating in soft x-ray region  

SciTech Connect

We present a realization of the sinusoidal transmission function using a series of zigzag-profiled strips where the transmission takes on the binary values 0 and 1 in a two-dimensional distribution. A zigzag transmission grating of 1000 line/mm has been fabricated and demonstrated on the soft x-ray beam of synchrotron radiation. The axial single-order diffraction indicates that the zigzag transmission grating is adequate for spectroscopic application.

Zang, H. P.; Wang, C. K. [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Gao, Y. L.; Zhou, W. M.; Kuang, L. Y.; Wei, L.; Fan, W.; Zhang, W. H.; Zhao, Z. Q.; Cao, L. F.; Gu, Y. Q.; Zhang, B. H. [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Jiang, G. [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Zhu, X. L.; Xie, C. Q. [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China); Zhao, Y. D.; Cui, M. Q. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2012-03-12

168

Spectral characteristics of plane multilayer amplitude diffraction gratings for the soft x-ray range  

Microsoft Academic Search

Several spectral characteristics of plane multilayer amplitude molybdenum---silicon diffraction gratings (1000 and 2000 lines mm-1), fabricated by electron-beam lithography, were determined with a broadband laser-plasma source of soft x-rays. The gratings, with the multilayer structure period 11.5 nm, were investigated at near-normal incidence and at an angle of incidence of 36o in a quasi-stigmatic spectrograph system with moderate dispersion. The

P. Troussel; S. Bac; Nikolai N. Kolachevsky; M. M. Mitropol'skii; Evgenii N. Ragozin

1996-01-01

169

An x-ray diffraction study of ribosome structure.  

PubMed

Dense gels of E. coli 70 S ribosomes, their 50 S subunits, CM-like particles, RNP strands and their fragments, 38 S particles obtained from RNP strand folding upon addition of Mg2+ ions, and of unoriented salt-free and free rRNA sodium and magnesium salts were studied by X-ray diffraction. It was shown that under dense gel conditions RNA molecules contained in ribosomes unfolded by desalting, like all other particles considered here, have helical regions. Under these conditions free desalted RNA has no helical regions. Experimental data on X-ray scattering at medium angles were compared with the diffraction curves calculated for homogeneous prolate and oblate ellipsoids, for various ellipsoids containing a dense region or an internal cavity, and for ellipsoids containing internal periodic regions. The results indicate that the internal structure of the 50 S ribosome is periodic, i. e., its components form a periodic lattice. The lattice spacings are approximately 42 and 28 A with a 0.8g/g dry weight sample water content. When the 50 S particle water content drops below 0.2 g/g dry weight the periodic structure is disrupted. This disruption is reversible. It was shown that CM-like particles at high ionic strenght (2 M LiCl) have approximately the same internal periodicity as the 50 S particles, but in contrast they lose this periodicity at low ionic strength (10-2M tris-HCl and 5-10-3 M MgCl2). PMID:1092999

Dolgov, A D; Ivanov, D A; Kapitonova, K A; Mokul'skii, M A

1975-01-01

170

In situ observation of x-ray irradiation effect by using a multiwave x-ray diffraction phenomenon  

SciTech Connect

In situ observation of the complex scattering amplitude of x-ray specular reflection (amplitude reflectivity) was performed by using a method with a multiwave x-ray diffraction phenomenon. The method can be applied to the noncrystalline layers on a single crystal and allows us to determine its amplitude reflectivity with only a 0.01 degree of crystal rotation, that is, the area irradiated by the incident x rays is almost unchanged during the measurement. We used this method to observe an irradiation effect induced by monochromatic synchrotron x-rays that occurred on a Si(001) single crystal covered with a native oxide layer. The obtained time evolution of the amplitude reflectivities exhibited counterclockwise behavior in the complex plane, indicating that the thickness of the noncrystalline layer on the crystalline substrate was increased by the irradiation.

Yashiro, Wataru [Department of Advanced Materials Science, Graduate School of Frontier Sciences, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Yoda, Yoshitaka [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-gun, Sayo-cho, Hyogo 679-5198 (Japan); Miki, Kazushi [Organic Nanomaterials Center, National Institute for Material Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Takahashi, Toshio [The Institute for Solid State Physics, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)

2011-11-15

171

Micro X-ray diffraction analysis of thin films using grazing-exit conditions.  

PubMed

An X-ray diffraction technique using a hard X-ray microbeam for thin-film analysis has been developed. To optimize the spatial resolution and the surface sensitivity, the X-ray microbeam strikes the sample surface at a large glancing angle while the diffracted X-ray signal is detected with a small (grazing) exit angle. Kirkpatrick-Baez optics developed at the Photon Factory were used, in combination with a multilayer monochromator, for focusing X-rays. The focused beam size was about 10 x 10 micro m. X-ray diffraction patterns of Pd, Pt and their layered structure were measured. Using a small exit angle, the signal-to-background ratio was improved due to a shallow escape depth. Under the grazing-exit condition, the refraction effect of diffracted X-rays was observed, indicating the possibility of surface sensitivity. PMID:15263691

Noma, T; Iida, A

1998-05-01

172

Nanostructured diffractive optical devices for soft X-ray microscopes  

NASA Astrophysics Data System (ADS)

The new transmission X-ray microscope (TXM) installed at the BESSY II electron storage ring uses an off-axis transmission zone plate (OTZ) as diffractive and focusing element of the condenser-monochromator setup. A high resolution micro-zone plate (MZP) forms a magnified image on a CCD-detector. Both, the OTZ with an active area of up to 24mm2 and the MZP with zone widths as small as 25nm are generated by a process including electron beam lithography (EBL), dry etching and subsequent electroplating of nickel on top of silicon membrane substrates with about 100-150nm thickness. The combination of a larger zone width and the usage of nickel zone structures allows to increase the diffraction efficiency of the condenser element at least by a factor of 3 compared to the earlier used KZP7 condenser zone plate in the TXM at BESSY I. Groove diffraction efficiencies of 21.6% and 14.7% were measured for MZP objectives with /40 and 25nm outermost zone width, respectively.

Hambach, D.; Peuker, M.; Schneider, G.

2001-07-01

173

Early stages of formation of the AgNi(111) interface studied by grazing incidence x-ray diffraction and x-ray photoelectron diffraction  

Microsoft Academic Search

Ultra-thin Ag\\/Ni(111) reconstructed interfaces have been revisited by a combination of in-situ grazing incidence x-ray diffraction (GIXD) and x-ray photoelectron diffraction (XPD) in order to determine the growth mode and to evaluate the interface spacing. Evidence for predominance of single-layer growth in the early stages was obtained through the analysis of the x-ray diffraction rods from the Ag\\/Ni(111) (52×52)R13.9o reconstructed

C. Chambon; A. Coati; M. Sauvage-Simkin; Y. Garreau; J. Creuze; A. Verdini; A. Cossaro; L. Floreano; A. Morgante

2011-01-01

174

Bent Crystals for Diffraction Enhanced X Ray Imaging with a Divergent Source  

NASA Astrophysics Data System (ADS)

Phase sensitive X ray imaging methods have been recently developed. Diffraction Enhanced X ray Imaging technique has proved to offer valuable advantages when applied in mammography using Synchrotron Radiation. It is our interest to apply this technique using a X ray tube, which has an angular aperture of 20°. The requirements for a suitable optical system are discussed.

Sanmiguel, R. E.; Kuper, K.; Besch, H. J.; Plothow-Besch, H.

2004-09-01

175

Rapid qualitative phase analysis in highly textured thin films by x-ray diffraction.  

PubMed

Phase analysis of highly out-of-plane textured specimens using x-ray diffraction is usually complicated due to the disappearance of most of the x-ray peaks in a common theta/2 theta diffraction geometry. In this paper, we propose a technique, where powderlike spectra of textured samples are obtained by multiaxial x-ray diffraction scans. This technique is a simple, yet powerful method which allows for significant improvement in thin film characterization and provides several types of information about the samples, such as the rapid qualitative identification of phases using common powder x-ray diffraction spectra databases, texture distribution, and quantitative residual stress analysis. PMID:18447532

Borgia, Cesare; Olliges, Sven; Spolenak, Ralph

2008-04-01

176

Laser-Stimulated Luminescence Used to Measure X-ray Diffraction of a Contracting Striated Muscle  

NASA Astrophysics Data System (ADS)

An integrating x-ray area detector that operates on the basis of laser-stimulated luminescence was used in a diffraction study of muscle contraction. The area detector has a dynamic range of 1 to 105, a sensitivity about 60 times greater with approximately 1/300 as much fog background as x-ray film. It is erasable and reusable but, like film, can integrate at a practically unlimited counting rate. The high sensitivity and wide dynamic range of the detector resulted in a sufficient reduction in the exposure time to make possible the recording of a clear x-ray diffraction pattern, with up to 2.0-nanometer axial spacing, from a contracting frog skeletal muscle in as little as 10 seconds with synchrotron radiation. During the isometric contraction of the muscle, most of the actin diffraction lines increased in intensity without noticeable changes in their peak positions. Changes also occurred in diffraction intensities from the myosin heads. The results indicate that during contraction the structure of the actin filaments differs from that in the rigor state, suggesting a possible structural change in the actin subunits themselves; the myosin heads during contraction retain the axial periodicity of the myosin filament and become aligned in a more perpendicular manner to the actin filaments.

Amemiya, Yoshiyuki; Wakabayashi, Katsuzo; Tanaka, Hidehiro; Ueno, Yutaka; Miyahara, Junji

1987-07-01

177

Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials  

SciTech Connect

An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN{sub 2}) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90 MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C{sub 60} was used to test the sample cooling unit. It shows that the phase of the C{sub 60} film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T=255 K.

Kulriya, P. K.; Singh, F.; Tripathi, A.; Ahuja, R.; Kothari, A.; Dutt, R. N.; Mishra, Y. K.; Kumar, Amit; Avasthi, D. K. [Inter-University Accelerator Centre, P.O. Box 10502, New Delhi 110067 (India)

2007-11-15

178

Temperature measurements of shocked crystals by use of nanosecond X-ray diffraction  

SciTech Connect

Over the past few years we have been pioneering the use of sub-nanosecond X-ray diffraction to determine the phase and compression of shocked crystals. It is well known that the deviation of atoms from their ideal lattice sites due to thermal motion reduces the integrated intensity within diffraction peaks - the so-called Debye-Waller effect, and thus it is pertinent to investigate whether line ratios might be sufficiently sensitive to be used as a viable temperature diagnostic. Clearly the matter is not completely straight-forward, as the Debye frequency of a solid also varies under compression. In our initial investigations we have calculated the ratios of intensities of high-order reflections assuming various forms of the Grueneisen parameter, and have also compared these results with those obtained from Molecular Dynamics simulations. Given the photon energies of nanosecond X-ray pulses that can currently be produced, we comment on the experimental feasibility of the technique.

Murphy, William J.; Higginbotham, Andrew; Wark, Justin S. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom); Park, Nigel [Material Modelling Group, AWE, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

2007-12-12

179

Unit cell determination in CuZr martensite by electron microscopy and X-ray diffraction  

SciTech Connect

As several other binary alloy compounds, stoichiometric CuZr has a B2 phase with a CsCl type bcc based structure. In the present system this phase appears as a line compound between 715 C and 935 C. Rapid cooling to below 140 C transforms this phase into at least two monoclinic structures which have been shown to have martensitic characteristics, not unusual for B2 phase alloys, including shape memory behavior. Unit cell dimensions for both monoclinic phases, one about twice the size of the other, were previously suggested on the basis of powder X-ray diffractometry and limited electron microscopy results. The aim of the current investigation was to confirm or correct these unit cells by extensive selected area electron diffraction (SAED), high resolution electron microscopy (HREM) and improved fitting procedures of the existing X-ray diffraction data. The crystallographic relation between parent and product phases will also be discussed.

Schryvers, D.; Seo, J.W. [RUCA, Antwerpen (Belgium); Firstov, G.S.; Koval, Yu.N. [National Academy of Sciences, Kiev (Ukraine). Inst. for Metal Physics; Humbeeck, J. Van [K.U. Leuven, Heverlee (Belgium)

1997-05-15

180

X-ray diffraction applications in thin films and (100) silicon substrate stress analysis  

Microsoft Academic Search

Silicon is used as a substrate for X-ray mirrors for correct imaging. The substrate needs to be mechanically bent to produce a certain curvature in order to condition and focus the X-ray beam. The X-rays impinge a mirror at very shallow angles, in order to reduce the amount of intensity loss in the diffraction process. The X-ray mirrors need to

James D Rachwal

2010-01-01

181

In-situ X-ray diffraction system using sources and detectors at fixed angular positions  

Microsoft Academic Search

An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the

David M. Gibson; Walter M. Gibson; Huapeng Huang

2007-01-01

182

Real-time Studies of Shocked Polycrystalline Materials with Single-Pulse X-ray Diffraction  

NASA Astrophysics Data System (ADS)

Recent advances in pulsed x-ray diffraction (XRD) diagnostic techniques have enabled real-time XRD studies of atomic-scale mechanisms within shocked polycrystalline materials. The direct correlation between solid-state structures and their associated XRD patterns enables direct observation of a material's bulk properties, including phase, grain-size distribution, texture, and micro-strain, during the very short time interval of shock-induced pressure loading. For shock-compressed polycrystalline solids, real time single-pulse XRD probes a macroscopic sample volume, and the measured diffraction pattern is the sum of the responses from the microscopic coherently diffracting domains. These experiments have utilized a Marx-generated, cable-coupled, needle-and-washer diode that emits a 40 ns pulse of line-and-bremsstahlung x-rays. The x-rays are collimated by a circular pinhole, and detected by an image plate or CCD camera coupled to a phosphor. The line emission is selectable to either 0.71 A or 0.56 A, and the hard bremsstahlung direct beam provides a zero-order reference mark in the image. Results from studies of shock-loaded materials including aluminum, tin, and zirconium are shown. Planned experiments and future diagnostic development are discussed.

Morgan, Dane

2011-06-01

183

Determination of Anisotropic Diamagnetic Susceptibility Using X-ray Diffraction  

NASA Astrophysics Data System (ADS)

We present a facile method for determining the anisotropic diamagnetic susceptibility of biaxial crystals by performing X-ray diffraction measurements. The proposed method is based on the fact that the amplitude of fluctuations in a crystallographic axis under a magnetic field depends on the direction of the field with respect to the susceptibility axes. By calculating the magnetic energies of a crystal under static and rotating magnetic fields, we determined the relationship of the half-width of the diffraction spots corresponding to the (hkl) planes with the anisotropic magnetic susceptibilities ?1-?2 and ?2-?3 for the static field and ?1-?2 and ?1-?3 for the rotating field, where ?1 > ?2 > ?3. We have shown that the absolute values of the anisotropic diamagnetic susceptibilities can be determined if the size of the microcrystals is known, whereas only the ratio (?2-?3)/(?1-?2) or (?1-?3)/(?1-?2) can be determined if the microcrystal size is unknown.

Kimura, Tsunehisa; Song, Guangjie; Matsumoto, Kenji; Fujita, Keiji; Kimura, Fumiko

2012-04-01

184

Fabrication of X-ray Mirror for Hard X-ray Diffraction Limited Nanofocusing  

Microsoft Academic Search

We designed, fabricated and evaluated a total-reflection mirror having a designed focal size of 28 nm at 15keV. Line-focus tests on the fabricated mirror were carried out at the 1-km-long beamline (BL29XUL) of SPring-8. Nearly diffraction-limited performance with a full width at half maximum spot size of 30 nm was realized at 15 keV. We are planning to fabricate multilayer-coated

Hirokatsu Yumoto; Hidekazu Mimura; Satoshi Matsuyama; Soichiro Handa; Akihiko Shibatani; Keiko Katagishi; Kazuya Yamamura; Yasuhisa Sano; Katsuyoshi Endo; Yuzo Mori; Makina Yabashi; Yoshinori Nishino; Kenji Tamasaku; Tetsuya Ishikawa; Kazuto Yamauchi

2007-01-01

185

Flash X-Ray Diffraction System for Fast, Single-PulseTemperature and Phase Transition Measurements (Pre-print)  

SciTech Connect

A new, fast, single-pulse diagnostic for determining phase transitions and measuring the bulk temperature of polycrystalline metal objects has been developed. The diagnostic consists of a 37-stage Marx bank with a cable-coupled X-ray diode that produces a 35-ns pulse of mostly 0.71-{angstrom} monochromatic X rays and a P-43 fluor coupled to a cooled, charge-coupled device camera by a coherent fiber-optic bundle for detection of scattered X rays. The X-ray beam is collimated to a 1{sup o} divergence in the scattering plane with the combination of a 1.5-mm tungsten pinhole and a 1.5-mm-diameter molybdenum anode. X rays are produced by a high-energy electron beam transiting inward from the cathode to the anode in a needle-and-washer configuration. The anode's characteristic K-{alpha} X-ray emission lines are utilized for this diffraction system. The X-ray anode is heavily shielded in all directions other than the collimated beam. The X-ray diode has a sealed reentrant system, allowing X rays to be produced inside a vacuum containment vessel, close to the sample under study.

Michael J. Madlener; Dane V. Morgan

2007-06-12

186

A comparison of different methods for x-ray diffraction line broadening analysis of Ti and Ag UHV deposited thin films: nanostructural dependence on substrate temperature and film thickness  

NASA Astrophysics Data System (ADS)

The influence of substrate temperature and film thickness on the nanostructure of titanium (HCP) and silver (FCC) thin films deposited on glass substrates under UHV conditions by electron beam evaporation is investigated. The preferred orientation, nanostrain and stacking and twin fault probabilities in Ag and Ti films are determined as a function of film thickness and substrate temperature. A (111) preferred orientation is observed for silver films, which is dependent on both the film thickness and substrate temperature, with the highest value at a substrate temperature of 500 K. Ti/glass films showed a (002) preferred orientation. Nanostructural parameters such as the crystallite size (size of coherently diffracting domains) and nanostrain are evaluated using the Scherrer and Stocks-Wilson relations, the Williamson-Hall plot, and the single-Voigt (SV), double-Voigt (DV) and Warren-Averbach (WA) methods. Analysis of the results obtained using these methods showed that the most suitable approaches to x-ray diffraction line broadening analysis, applicable to both FCC and HCP polycrystalline thin film structures, are SV, DV and WA. The results show that the crystallite sizes increase with substrate temperature and film thickness, while the nanostrain and lattice constants decrease with thickness. The crystallite size distribution function was obtained from the size broadened part of the DV function, and the results show a shift in the maximum to larger sizes with increasing temperature and thickness.

Savaloni, H.; Gholipour-Shahraki, M.; Player, M. A.

2006-05-01

187

Mapping a Mantle Xenolith Using Micro X-ray Diffraction  

NASA Astrophysics Data System (ADS)

With the advent of Micro X-ray diffraction (?XRD), mineral mapping is now possible at the thin section scale, using crystal structural rather than chemical properties. To test the effectiveness of this technique, a Brüker D8 Discover ?XRD was used to create mineral maps from two garnet lherzolite xenoliths from the Bultfontein kimberlite recovered on the Boshof road dumps (Kimberley, South Africa). This technique generated a 2D representation of the major mineralogy (olivine + garnet + clinopyroxene + orthopyroxene + phlogopite); it also enabled estimation of the modal proportions of each mineral. For one polished section, two sets of ?XRD data were collected along grids having spacing of 0.5 mm (1148 points) and 1.5 mm (516 points), respectively. The 0.5 mm spacing coincided with the X-ray beam diameter, leaving no gaps in coverage. Data were also collected using a grid of 1.5 mm spacing to examine the effectiveness of a low- resolution map, which would be advantageous to decrease the time required for data collection and processing. To test the potential for automation of the method, data were collected for a second polished thin section, using the high resolution grid (0.5 mm spacing, 3312 data points). General Area Diffraction Detection System (GADDS) images were collected and processed at each step. Debye rings were integrated along small "slices" of 2? to yield the total number of counts in that area. The 2? ranges used to identify each phase were chosen such that they coincided with regions where there was no overlap with peaks from any of the other four major phases. To compensate for variable orientation of the grains in the thin sections, several d-spacings (2? ranges) were integrated for each mineral, and then added together to create five "overall" mineral maps. To create final maps, minerals were determined to be 'present' in cells where the number of counts was above a threshold level in the "overall" map for that mineral. The maps provided fairly accurate estimates of the modal mineralogy (when compared to point counts), with the added benefit of recording the spatial distribution. Some areas of the thin sections were not assigned to any mineral, due to the orientation of the mineral not satisfying Bragg's law, or the mineral being highly altered in that area of the thin section. Further development of this technique will focus on refining the quality of the final maps. This technique could potentially be used to provide information about preferred orientation of minerals in mantle xenoliths and other rocks, or to distinguish minerals which exist in different hydrated states.

Harwood, B. P.; Flemming, R. L.; Stachel, T.

2009-05-01

188

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

NASA Astrophysics Data System (ADS)

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

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

2003-06-01

189

Soft X-ray diffraction microscopy of a frozen hydrated yeast cell.  

PubMed

We report the first image of an intact, frozen hydrated eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezing the specimen in liquid ethane and maintaining it below -170 degrees C, artifacts due to dehydration, ice crystallization, and radiation damage are greatly reduced. In this example, coherent diffraction data using 520 eV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25 nm. This demonstration represents an important step towards high resolution imaging of cells in their natural, hydrated state, without limitations imposed by x-ray optics. PMID:20365955

Huang, Xiaojing; Nelson, Johanna; Kirz, Janos; Lima, Enju; Marchesini, Stefano; Miao, Huijie; Neiman, Aaron M; Shapiro, David; Steinbrener, Jan; Stewart, Andrew; Turner, Joshua J; Jacobsen, Chris

2009-11-05

190

Soft X-Ray Diffraction Microscopy of a Frozen Hydrated Yeast Cell  

SciTech Connect

We report the first image of an intact, frozen hydrated eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezing the specimen in liquid ethane and maintaining it below -170 deg. C, artifacts due to dehydration, ice crystallization, and radiation damage are greatly reduced. In this example, coherent diffraction data using 520 eV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25 nm. This demonstration represents an important step towards high resolution imaging of cells in their natural, hydrated state, without limitations imposed by x-ray optics.

Huang Xiaojing; Nelson, Johanna; Lima, Enju; Miao, Huijie; Steinbrener, Jan; Stewart, Andrew; Turner, Joshua J.; Jacobsen, Chris [Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800 (United States); Kirz, Janos [Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800 (United States); Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Marchesini, Stefano; Shapiro, David [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Neiman, Aaron M. [Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794-5215 (United States)

2009-11-06

191

Scandium(III) hydration in aqueous solution from X-ray diffraction and X-ray absorption fine structure measurements  

Microsoft Academic Search

Measurements of X-ray diffraction (XD) on 1 and 3 M Sc(CIO4)3 aqueous solutions and of X-ray absorption fine structure (XAFS) on a 4.6 M Sc(CF3SO3)3 aqueous solution have been made at room temperature. Both the XD and XAFS data have revealed that about seven water molecules are bound to a Sc3+ ion with a Sc3+?H2O distance of 2.18 Å. The

Toshio Yamaguchi; Mami Niihara; Toshiyuki Takamuku; Hisanobu Wakita; Hitoshi Kanno

1997-01-01

192

In situ X-ray diffraction and X-ray absorption studies of high-rate lithium-ion batteries  

Microsoft Academic Search

A combination of in situ synchrotron X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) was used to study a two-electrode lithium-ion cell made from electrodes from a high-rate lithium-ion battery. The cathode was LiNi0.85Co0.15O2. Both the XRD and the XAS were done in the transmission mode. XAS was done while the cell was charged at the C\\/2 rate to 4.5V.

M Balasubramanian; X Sun; X. Q Yang; J McBreen

2001-01-01

193

Analysis of Slurry-Coating Effectiveness of CL20 Using Grazing Incidence X-ray Diffraction  

Microsoft Academic Search

A grazing incidence X-ray diffraction technique was developed to characterize the effectiveness of the coating of the solid particles by the binder in energetic formulations and was used in conjunction with scanning electron microscopy, traditional wide-angle X-ray diffraction, and specific gravity measurements to probe the microstructure of PAX-12 granules. The grazing incidence X-ray technique was applied to granules formed upon

BERTON L. GREENBERG; DILHAN M. KALYON; MELEK EROL; MARK MEZGER; KENNETH LEE; SCOTT LUSK

2003-01-01

194

Characterization of high-resolution diffractive X-ray optics by ptychographic coherent diffractive imaging.  

PubMed

We have employed ptychographic coherent diffractive imaging to completely characterize the focal spot wavefield and wavefront aberrations of a high-resolution diffractive X-ray lens. The ptychographic data from a strongly scattering object was acquired using the radiation cone emanating from a coherently illuminated Fresnel zone plate at a photon energy of 6.2 keV. Reconstructed images of the object were retrieved with a spatial resolution of 8 nm by combining the difference-map phase retrieval algorithm with a non-linear optimization refinement. By numerically propagating the reconstructed illumination function, we have obtained the X-ray wavefield profile of the 23 nm round focus of the Fresnel zone plate (outermost zone width, ?r = 20 nm) as well as the X-ray wavefront at the exit pupil of the lens. The measurements of the wavefront aberrations were repeatable to within a root mean square error of 0.006 waves, and we demonstrate that they can be related to manufacturing aspects of the diffractive optical element and to errors on the incident X-ray wavefront introduced by the upstream beamline optics. PMID:22108984

Vila-Comamala, Joan; Diaz, Ana; Guizar-Sicairos, Manuel; Mantion, Alexandre; Kewish, Cameron M; Menzel, Andreas; Bunk, Oliver; David, Christian

2011-10-24

195

Cinnamomin: separation, crystallization and preliminary X-ray diffraction study.  

PubMed

Cinnamomin from Cinnamonum camphora seeds, a type II ribosome-inactivating protein that interferes with protein biosynthesis in mammalian cells, can induce the apoptosis of carcinoma cells and be used as an insecticide. A rapid and improved method has been developed for the extraction and purification of cinnamomin from camphora seed. Purification of cinnamomin is achieved with two successive steps of hydrophobic interaction chromatography carried out on a fast protein liquid chromatography (FPLC) system. Crystals suitable for X-ray diffraction analysis were obtained by vapor diffusion method. A complete data set at 2.8 A resolution has been collected. Data indexation and refinement indicate that the crystal is orthorhombic with space group P2(1)2(1)2(1) and unit cell dimensions a = 52.39 A, b = 126.33 A, c = 161.45 A. There are two molecules per asymmetric unit. Initial phasing by molecular replacement method yielded a solution, which will contribute to the structure determination. A molecular model will further the understanding of the mechanism of cinnamomin function. The latter will be combined with bio-informatics to facilitate the medical and other applications of cinnamomin. PMID:17404804

Wang, T; Zou, Y-S; Zhu, D-W; Azzi, A; Liu, W-Y; Lin, S-X

2007-04-04

196

X-ray micro-beam study of reliability in aluminum-copper interconnect lines  

NASA Astrophysics Data System (ADS)

X-ray photoemission spectroscopy and x-ray diffraction are powerful techniques widely used in materials research. The advent of synchrotron radiation facilities as high brightness x-ray sources and recent advances in x-ray optics have extended these techniques to spatially resolved measurements with sub-micron resolution. We have used two such facilities to study two major reliability problems in integrated circuit interconnect technology: electromigration and mechanical stress induced problems. MAXIMUM at the Advanced Light Source (ALS) is a scanning photoemission microscope based on multilayer coated normal incidence optics. It acquires images of surfaces that map chosen spectral features from photoelectron emission spectra. In situ electromigration experiments were performed in the ultra high vacuum chamber of MAXIMUM on patterned Al-Cu lines. The results demonstrate a Cu rich surface precipitation, changes in Cu distribution as a result of the electromigration process and the detection of shallow voids under the surface oxide layer. The X-ray micro-beam facility at the Advanced Photon Source (APS) uses diffractive Fresnel Zone Plates to focus intense undulator light into a sub-micron size beam. Microdiffraction experiments were performed to map the stress distribution along patterned Al-Cu lines with a ˜1 ?m resolution for the first time. Diffraction patterns from single grains were recorded on an x-ray CCD camera and techniques developed to analyze the two dimensional micro-diffraction data for strain-stress analysis. An increase of grain to grain and intra-grain stress variation was found after accelerated electromigration testing. Contrary to predictions, no long range variation of stress due to electromigration was observed. These observations demonstrate the usefulness and potential of x-ray micro-characterization techniques in the electronic materials area.

Solak, Harun Hadi

197

X-ray diffraction-based electronic structure calculations and experimental x-ray analysis for medical and materials applications  

NASA Astrophysics Data System (ADS)

This thesis includes x-ray experiments for medical and materials applications and the use of x-ray diffraction data in a first-principles study of electronic structures and hyperfine properties of chemical and biological systems. Polycapillary focusing lenses were used to collect divergent x rays emitted from conventional x-ray tubes and redirect them to form an intense focused beam. These lenses are routinely used in microbeam x-ray fluorescence analysis. In this thesis, their potential application to powder diffraction and focused beam orthovoltage cancer therapy has been investigated. In conventional x-ray therapy, very high energy (˜ MeV) beams are used, partly to reduce the skin dose. For any divergent beam, the dose is necessarily highest at the entry point, and decays exponentially into the tissue. To reduce the skin dose, high energy beams, which have long absorption lengths, are employed, and rotated about the patient to enter from different angles. This necessitates large expensive specialized equipment. A focused beam could concentrate the dose within the patient. Since this is inherently skin dose sparing, lower energy photons could be employed. A primary concern in applying focused beams to therapy is whether the focus would be maintained despite Compton scattering within the tissue. To investigate this, transmission and focal spot sizes as a function of photon energy of two polycapillary focusing lenses were measured. The effects of tissue-equivalent phantoms of different thicknesses on the focal spot size were studied. Scatter fraction and depth dose were calculated. For powder diffraction, the polycapillary optics provide clean Gaussian peaks, which result in angular resolution that is much smaller than the peak width due to the beam convergence. Powder diffraction (also called coherent scatter) without optics can also be used to distinguish between tissue types that, because they have different nanoscale structures, scatter at different angles. Measurements were performed on the development of coherent scatter imaging to provide tissue type information in mammography. Atomic coordinates from x-ray diffraction data were used to study the nuclear quadrupole interactions and nature of molecular binding in DNA/RNA nucleobases and molecular solid BF3 systems.

Mahato, Dip Narayan

198

Combined Microstructure X-ray Optics: Multilayer Diffraction Gratings.  

National Technical Information Service (NTIS)

Multilayers are man-made microstructures engineered to vary in depth that are now of sufficient quality to be used as x-ray, soft x-ray and extreme ultraviolet optics. Gratings are in-plane man-made microstructures which have been used as optic elements f...

T. W. Barbee

1988-01-01

199

IDENTIFICATION OF COMPOUNDS IN PARTICULATE POLLUTION BY X-RAY DIFFRACTION  

EPA Science Inventory

X-ray diffraction is a valuable tool for the identification of crystalline compounds in a multicomponent sample. Two x-ray diffraction techniques (Seeman-Bohlin and Bragg-Brentano) were examined for the identification of small amounts of material deposited on low-mass substrates....

200

X-RAY DIFFRACTION CHARACTERIZATION OF RESIDUAL STRESSES PRODUCED BY SHOT PEENING  

Microsoft Academic Search

A brief overview of the theory and practice of x-ray diffraction residual stress measurement as applied to shot peened materials is presented. The unique ability of x-ray diffraction methods to determine both the macroscopic residual stress and the depth and magnitude of the cold worked layer produced by shot peening is described. The need to obtain a complete description of

Paul S. Prevéy

1990-01-01

201

X-Ray Diffraction and the Discovery of the Structure of DNA  

ERIC Educational Resources Information Center

|A method is described for teaching the analysis of X-ray diffraction of DNA through a series of steps utilizing the original methods used by James Watson, Francis Crick, Maurice Wilkins and Rosalind Franklin. The X-ray diffraction pattern led to the conclusion of the basic helical structure of DNA and its dimensions while basic chemical…

Crouse, David T.

2007-01-01

202

Ultrafast Time Resolved X-ray Diffraction Studies of Laser Heated Metals and Semiconductors  

Microsoft Academic Search

Time resolved hard x-ray diffraction has been employed to study the dynamics of lattice structure deformation. When laser pulse energy is deposited in a material it generates a non uniform transient temperature distribution, which alters the lattice structure of the crystal. The deformed crystal lattice will change the angle of diffraction for a monochromatic x-ray beam. We report picosecond and

Peilin Chen; I. V. Tomov; P. M. Rentzepis

1998-01-01

203

Single order x-ray diffraction with binary sinusoidal transmission grating  

SciTech Connect

All existing x-ray dispersive devices including crystals, multilayers and diffraction gratings generate spectra in multiple orders. In this letter the authors describe how an axis symmetrically distributed sinusoidal-shaped aperture with binary transmittance values can be used to disperse x rays and with a superior diffraction pattern where, along its symmetry axis, all higher-order diffractions can be effectively suppressed. Hence this sophisticated dispersive element generates pure soft x-ray spectra in the first diffraction order, free from interference from higher diffraction orders.

Cao, L. F.; Foerster, E.; Fuhrmann, A.; Wang, C. K.; Kuang, L. Y.; Liu, S. Y.; Ding, Y. K. [X-ray Optics Group, Institute for Quantum Optics and Electronics, Friedrich-Schiller-University, Max-Wien-Platz 1, 07743 Jena (Germany) and Research Center of Laser Fusion, National Key Laboratory of Laser Fusion, Mianyang, Sichuan 621900 (China); X-ray Optics Group, Institute for Quantum Optics and Electronics, Friedrich-Schiller-University, Max-Wien-Platz 1, 07743 Jena (Germany); Research Center of Laser Fusion, National Key Laboratory of Laser Fusion, Mianyang, Sichuan 621900 (China)

2007-01-29

204

TYPING SUPERNOVA REMNANTS USING X-RAY LINE EMISSION MORPHOLOGIES  

SciTech Connect

We present a new observational method to type the explosions of young supernova remnants (SNRs). By measuring the morphology of the Chandra X-ray line emission in 17 Galactic and Large Magellanic Cloud SNRs with a multipole expansion analysis (using power ratios), we find that the core-collapse SNRs are statistically more asymmetric than the Type Ia SNRs. We show that the two classes of supernovae can be separated naturally using this technique because X-ray line morphologies reflect the distinct explosion mechanisms and structure of the circumstellar material. These findings are consistent with recent spectropolarimetry results showing that core-collapse supernovae explosions are intrinsically more asymmetric.

Lopez, L. A.; Ramirez-Ruiz, E. [Department of Astronomy and Astrophysics, University of California Santa Cruz, 159 Interdisciplinary Sciences Building, 1156 High Street, Santa Cruz, CA 95064 (United States); Badenes, C. [Department of Astrophysical Sciences, Princeton University Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States); Huppenkothen, D. [Astronomical Institute, 'Anton Pannekoek', University of Amsterdam, P.O. Box 94249, 1090 GE Amsterdam (Netherlands); Jeltema, T. E. [UCO/Lick Observatories, 1156 High Street, Santa Cruz, CA 95064 (United States); Pooley, D. A., E-mail: lopez@astro.ucsc.ed [Astronomy Department, University of Wisconsin, 475 North Charter Street, Madison, WI 53706 (United States)

2009-11-20

205

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.

1986-06-01

206

Instrumentation of x-ray diffraction and materials research on the National Synchrotron Light Source. Final report  

SciTech Connect

MATRIX was organized in 1980 to formulate a research team to design and construct a beam line at NSLS for x-ray diffraction studies of materials. A versatile system was designed to allow a full range of experimental capabilities for wide angle x-ray scattering experiments including surface diffraction studies. The design and construction of the system has been completed. Testing of parts of the system was completed at CHESS and with x-ray sources or other equipment at member institutions. Installation of the beam line at NSLS is in progress and will proceed in parallel with the commissioning of the x-ray ring at NSLS. Full operation of the beam line is expected to be ready by December 1, 1984 being limited only by the source power of NSLS at that time. Useful experiments could be started if the power is at least 2 GeV and 100ma. The MATRIX beam line was one of the first x-ray beam lines to see light in the beam line in early spring of 1984. In July of 1984, the MATRIX beam line as the first port at NSLS to have a monochromatic beam and to scan part of the spectrum from the source. As part of this contract, six publications have resulted from the various projects. Three publications are concerned directly with the beam line and/or its operation while the other three publications are the result of research associated with the project.

Liedl, G.L.

1984-11-01

207

Double crystal dispersion monochromator for X-ray plane wave diffraction  

Microsoft Academic Search

A double crystal monochromator for X-ray plane-wave diffraction is proposed. It is possible to cut the second monochromator in such a way that the diffraction on a monocrystalline specimen can be made nondispersive.

V. V. Lider

1991-01-01

208

Femtosecond x-ray line emission from specially designed targets irradiated by short laser pulses  

NASA Astrophysics Data System (ADS)

The invention of high-power ultra short pulse lasers has opened way to investigations aimed at creation of a new type of bright x-ray source for different applications including material science and time resolved x-ray diffraction for biology. The conversion efficiency of the laser energy incident onto a solid target into the x-ray emission depends on many factors, including the temporal profile of laser pulse. We report here the results of our theoretical and experimental investigations of the line x-ray emission from layer solid targets irradiated by ultra short laser pulses. The parameters of laser pre-pulse and target thickness are optimized in order to get the maximum laser energy conversion into the emission in the selected x-ray line. Multi-layer foils are proposed in order to increase the energy of K-? line emission from laser plasma simultaneously with shortening of x-ray pulse up to hundred femtoseconds. The emission is studied, both experimentally, and by means of analytical model and numerical simulations.

Andreev, Alexander A.; Nakano, Hidetoshi; Limpouch, Jiri

2004-01-01

209

Measuring Doppler Shifts of X-Ray Lines to Determine the Stellar Wind X-Ray Locations in OB Stars  

Microsoft Academic Search

For almost 20 years we have been trying to determine the source of the X-ray emission in OB stars. It is generally believed that this emission is caused by a distribution of stellar wind shocks. The AXAF grating spectrometers will provide the ultimate test of X-ray models. The shock model predicts that X-ray lines must be Doppler blue-shifted, hence, our

Wayne Waldron

1999-01-01

210

Diffraction-limited astronomical X-ray imaging and X-ray interferometry using multilayer optics  

Microsoft Academic Search

Soft X-ray telescopes constructed from normal-incidence multilayer mirrors have driven the tremendous progress in solar physics made over the last decade. Most notably, the SoHO EIT and TRACE instruments now provide high resolution images that can be used to construct detailed temperature and density maps of the solar corona; the imaging data are complementary to the high-resolution spectral data obtained

D. L. Windt; S. M. Kahn; G. E. Sommargren

2002-01-01

211

Analysis of diatomite sediments from a paleolake in central Mexico using PIXE, X-ray tomography and X-ray diffraction  

Microsoft Academic Search

Diatomite samples from paleolake Tlaxcala, in Central Mexico, have been analyzed using proton induced X-ray emission (PIXE), X-ray tomography and X-ray diffraction. Chiseled blocks were scanned with a 0.7 MeV proton beam, 0.1 mm in diameter, in 0.25 mm steps across the sediments. X-ray tomography with the same step sizes was then applied, in order to compare the concentrations obtained

J. Miranda; A. Oliver; G. Vilaclara; R. Rico-Montiel; V. M. Macías; J. L. Ruvalcaba; M. A. Zenteno

1994-01-01

212

Lensless Diffractive Imaging Using Tabletop Coherent High-Harmonic Soft-X-Ray Beams  

SciTech Connect

We present the first experimental demonstration of lensless diffractive imaging using coherent soft x rays generated by a tabletop soft-x-ray source. A 29 nm high harmonic beam illuminates an object, and the subsequent diffraction is collected on an x-ray CCD camera. High dynamic range diffraction patterns are obtained by taking multiple exposures while blocking small-angle diffraction using beam blocks of varying size. These patterns reconstruct to images with 214 nm resolution. This work demonstrates a practical tabletop lensless microscope that promises to find applications in materials science, nanoscience, and biology.

Sandberg, Richard L.; Paul, Ariel; Raymondson, Daisy A.; Haedrich, Steffen; Gaudiosi, David M.; Holtsnider, Jim; Tobey, Ra'anan I.; Cohen, Oren; Murnane, Margaret M.; Kapteyn, Henry C.; Song, Changyong; Miao Jianwei; Liu Yanwei; Salmassi, Farhad [JILA and Department of Physics, University of Colorado and NSF Engineering Research Center in Extreme Ultraviolet Science and Technology, Boulder, Colorado 80309 (United States); Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2007-08-31

213

A method for implementing the diffraction of a widely divergent X-ray beam  

SciTech Connect

A method for implementing the diffraction of a widely divergent characteristic X-ray beam from a standard X-ray tube with a linear focal spot was improved. X rays, passing through a diaphragm 30 {mu}m in diameter, diffract from a crystal adjacent to the diaphragm. The crystal, together with a photographic plate, rotates around the axis perpendicular to the plate. It is shown that the diffraction image is a set of hyperbolas in this case. The equations of the hyperbolas are obtained and investigated. A method for interpreting the diffraction images in the case of small crystal asymmetry is proposed.

Avetyan, K. T.; Arakelyan, M. M., E-mail: marakelyan@ysu.am [Yerevan State University (Armenia)

2008-11-15

214

Focusing Optics for High-Energy X-ray Diffraction.  

PubMed

Novel focusing optical devices have been developed for synchrotron radiation in the energy range 40-100 keV. Firstly, a narrow-band-pass focusing energy-tuneable fixed-exit monochromator was constructed by combining meridionally bent Laue and Bragg crystals. Dispersion compensation was applied to retain the high momentum resolution despite the beam divergence caused by the focusing. Next, microfocusing was achieved by a bent multilayer arranged behind the crystal monochromator and alternatively by a bent Laue crystal. A 1.2 micro m-high line focus was obtained at 90 keV. The properties of the different set-ups are described and potential applications are discussed. First experiments were performed, investigating with high spatial resolution the residual strain gradients in layered polycrystalline materials. The results underline that focused high-energy synchrotron radiation can provide unique information on the mesoscopic scale to the materials scientist, complementary to existing techniques based on conventional X-ray sources, neutron scattering or electron microscopy. PMID:15263483

Lienert, U; Schulze, C; Honkimäki, V; Tschentscher, T; Garbe, S; Hignette, O; Horsewell, A; Lingham, M; Poulsen, H F; Thomsen, N B; Ziegler, E

1998-05-01

215

Combined microstructure x-ray optics: Multilayer diffraction gratings  

Microsoft Academic Search

Multilayers are man-made microstructures engineered to vary in depth that are now of sufficient quality to be used as x-ray, soft x-ray and extreme ultraviolet optics. Gratings are in-plane man-made microstructures which have been used as optic elements for most of this century. Joining of these two optical elements to form combined microstructure optics has the potential for greatly enhancing

Barbee; T. W. Jr

1988-01-01

216

High-resolution projection image reconstruction of thick objects by hard x-ray diffraction microscopy  

SciTech Connect

Hard x-ray diffraction microscopy enables us to observe thick objects at high spatial resolution. The resolution of this method is limited, in principle, by only the x-ray wavelength and the largest scattering angle recorded. As the resolution approaches the wavelength, the thickness effect of objects plays a significant role in x-ray diffraction microscopy. In this paper, we report high-resolution hard x-ray diffraction microscopy for thick objects. We used highly focused coherent x rays with a wavelength of {approx}0.1 nm as an incident beam and measured the diffraction patterns of a {approx}150-nm-thick silver nanocube at the scattering angle of {approx}3 deg. We observed a characteristic contrast of the coherent diffraction pattern due to only the thickness effect and collected the diffraction patterns at nine incident angles so as to obtain information on a cross section of Fourier space. We reconstructed a pure projection image by the iterative phasing method from the patched diffraction pattern. The edge resolution of the reconstructed image was {approx}2 nm, which was the highest resolution so far achieved by x-ray microscopy. The present study provides us with a method for quantitatively observing thick samples at high resolution by hard x-ray diffraction microscopy.

Takahashi, Yukio [Frontier Research Base for Global Young Researchers, Frontier Research Center, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishino, Yoshinori [Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021 (Japan); Tsutsumi, Ryosuke [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Zettsu, Nobuyuki [Research Center for Ultra-precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Matsubara, Eiichiro [Department of Materials Science and Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8501 (Japan); Yamauchi, Kazuto [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Research Center for Ultra-precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Ishikawa, Tetsuya [RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2010-12-01

217

Real-time X-ray Diffraction Measurements of Shocked Polycrystalline Tin and Aluminum  

SciTech Connect

A new, fast, single-pulse x-ray diffraction (XRD) diagnostic for determining phase transitions in shocked polycrystalline materials has been developed. The diagnostic consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, producing line and bremsstrahlung x-ray emission in a 35-ns pulse. The characteristic K? lines from the selected anodes of silver and molybdenum are used to produce the diffraction patterns, with thin foil filters employed to remove the characteristic K? line emission. The x-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 3-mm by 6-mm spot and 1° full-width-half-maximum (FWHM) angular divergence in a Bragg-reflecting geometry. For the experiments described in this report, the angle between the incident beam and the sample surface was 8.5°. A Debye-Scherrer diffraction image was produced on a phosphor located 76 mm from the polycrystalline sample surface. The phosphor image was coupled to a charge-coupled device (CCD) camera through a coherent fiberoptic bundle. Dynamic single-pulse XRD experiments were conducted with thin foil samples of tin, shock loaded with a 1-mm vitreous carbon back window. Detasheet high explosive with a 2-mm-thick aluminum buffer was used to shock the sample. Analysis of the dynamic shock-loaded tin XRD images revealed a phase transformation of the tin beta phase into an amorphous or liquid state. Identical experiments with shock-loaded aluminum indicated compression of the face-centered-cubic (fcc) aluminum lattice with no phase transformation.

Dane V. Morgan, Don Macy, Gerald Stevens

2008-11-22

218

Real-time x-ray diffraction measurements of shocked polycrystalline tin and aluminum  

NASA Astrophysics Data System (ADS)

A new, fast, single-pulse x-ray diffraction (XRD) diagnostic for determining phase transitions in shocked polycrystalline materials has been developed. The diagnostic consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, producing line and bremsstrahlung x-ray emission in a 35 ns pulse. The characteristic K? lines from the selected anodes of silver and molybdenum are used to produce the diffraction patterns, with thin foil filters employed to remove the characteristic K? line emission. The x-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 3×6 mm2 spot and 1° full width half maximum angular divergence in a Bragg-reflecting geometry. For the experiments described in this report, the angle between the incident beam and the sample surface was 8.5°. A Debye-Scherrer diffraction image was produced on a phosphor located 76 mm from the polycrystalline sample surface. The phosphor image was coupled to a charge-coupled device camera through a coherent fiber-optic bundle. Dynamic single-pulse XRD experiments were conducted with thin foil samples of tin, shock loaded with a 1 mm vitreous carbon back window. Detasheet high explosive with a 2-mm-thick aluminum buffer was used to shock the sample. Analysis of the dynamic shock-loaded tin XRD images revealed a phase transformation of the tin beta phase into an amorphous or liquid state. Identical experiments with shock-loaded aluminum indicated compression of the face-centered-cubic aluminum lattice with no phase transformation.

Morgan, Dane V.; Macy, Don; Stevens, Gerald

2008-11-01

219

Diffraction-limited imaging in a scanning transmission x-ray microscope  

Microsoft Academic Search

We report the characterization of a scanning transmission X-ray microscope which makes use of an undulator X-ray source, a high resolution scanning stage, and a 45 nm outer zone width, > 10% diffraction efficiency Fresnel zone plate as the probe-forming optic at soft X-ray wavelengths (typically 3.64 nm). The modulation transfer function of the instrument is in good agreement with

C. Jacobsen; S. Williams; E. Anderson; M. T. Browne; C. J. Buckley; D. Kern; J. Kirz; M. Rivers; X. Zhang

1991-01-01

220

Highly intense monochromatic X-ray diffraction facility for high-pressure research at SPring8  

Microsoft Academic Search

Beamline BL10XU at SPring-8, designed for X-ray diffraction experiments using diamond anvil cells at high pressure and low\\/high temperature, is continuously upgraded. The X-ray source, optics, and attractive experimental equipment such as simultaneous measurement systems have been optimized over the past years. The high energy and high intensity monochromatic X-ray beams emitted by an undulator source, focused using a characteristic

Yasuo Ohishi; Naohisa Hirao; Nagayoshi Sata; Kei Hirose; Masaki Takata

2008-01-01

221

Methods for obtaining superresolution images in coherent x-ray diffraction microscopy  

SciTech Connect

Coherent x-ray diffraction microscopy (CXDM) using an x-ray free electron laser (XFEL) is expected to open up a new frontier of structural studies in materials science and biology, while radiation damage of samples under the extremely intense x rays is a matter of considerable concern. Two superresolution methods for CXDM proposed in this paper offer solutions of the problems by numerical data analysis. Promising results for future applications of CXDM with XFEL were obtained in a numerical simulation.

Takahashi, Yukio; Nishino, Yoshinori; Ishikawa, Tetsuya [Frontier Research Base for Global Young Researchers, Frontier Research Center, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); RIKEN SPring-8 Center, Kouto, Sayo, Sayo, Hyogo 679-5148 (Japan)

2007-09-15

222

Blazed diffraction gratings fabricated using X-ray lithography: fabrication, modeling and simulation  

Microsoft Academic Search

Diffraction gratings are used in optical communications devices, spectrographs, optical scanners, monochromators, and in other instances. Diffraction gratings are either transmission or reflection. Reflective gratings are, usually, either ruled or holographic. Blazed gratings (step-echelette or phase gratings) are non-planar gratings. We present the fabrication of blazed diffraction gratings using X-ray lithography. We model, theoretically, the development process of X-ray exposed

Paul Isaac Hagouel

2003-01-01

223

Beam-induced damage on diffractive hard X-ray optics.  

PubMed

The issue of beam-induced damage on diffractive hard X-ray optics is addressed. For this purpose a systematic study on the radiation damage induced by a high-power X-ray beam is carried out in both ambient and inert atmospheres. Diffraction gratings fabricated by three different techniques are considered: electroplated Au gratings both with and without the polymer mold, and Ir-coated Si gratings. The beam-induced damage is monitored by X-ray diffraction and evaluated using scanning electron microscopy. PMID:20975225

Nygård, K; Gorelick, S; Vila-Comamala, J; Färm, E; Bergamaschi, A; Cervellino, A; Gozzo, F; Patterson, B D; Ritala, M; David, C

2010-09-02

224

Applications of X-ray powder diffraction in materials chemistry.  

PubMed

X-ray powder diffraction is a standard technique in materials chemistry, yet it is often still used in the laboratory as a "one-hit" technique, e.g. for fingerprinting and following the progress of reactions. It is important, however, that the wealth of information available from powder data is not overlooked. While it is only possible here to scratch the surface of possibilities, a range of examples from our research is used to emphasize some of the more accessible techniques and to highlight successes as well as potential problems. The first example is the study of solid solution formation in the oxide systems Ba(3-3x)La(2x)V2O8 and Sr(4-x)Ba(x)Mn3O10 and in the silicate-hydroxyapatite bioceramic, Ca10(PO4)6-x(SiO4)x(OH)2-x. Database mining is also explored, using three phases within the pseudobinary phase diagram Li3SbO4-CuO as examples. All three phases presented different challenges: the structure of Li3SbO4 had been previously reported in higher symmetry than was actually the case, Li3Cu2SbO6 was found to be isostructural with Li2TiO3 but the cation ordering had to be rationalized, and Li3CuSbO5 was believed to be triclinic, presenting challenges in indexing the powder pattern. Quantitative phase analysis is briefly discussed, with the emphasis both on success (determination of amorphous phase content in a novel cadmium arsenate phase) and on possible failure (compositional analysis in bone mineral); the reasons for the problems in the latter are also explored. Finally, the use of an area detector system has been shown to be of value in the study of orientational effects (or lack of them) in non- and partially-ordered biomaterials, including p-HEMA, annulus fibrosis of lumbar discs, and keratin in the horn of cow's hooves. PMID:16211607

Skakle, Jan

2005-01-01

225

Near Edge X-Ray Absorption and X-Ray Photoelectron Diffraction Studies of the Structural Environment of Ge-Si Systems  

Microsoft Academic Search

Near edge X-ray absorption spectroscopy (XAS), X-ray photoelectron diffraction (XPD) and Auger electron diffraction (AED) are powerful techniques for the qualitative study of the structural and electronic properties of several systems. The recent development of a multiple scattering approach to simulating experimental spectra opened a friendly way to the study of structural environments of solids and surfaces. This article reviews

P. Castrucci; R. Gunnella; N. Pinto; R. Bernardini; M. de Crescenzi; M. Sacchi

2000-01-01

226

Optimized performance of graded multilayer optics for x-ray single-crystal diffraction  

Microsoft Academic Search

We present recent developments in the production of X-ray multilayer optics for Cu Kalpha laboratory single crystal diffraction equipment for protein crystallography and structural proteomics. The paper shows design, simulations and properties of Montel optics comprised of two elliptically bent focusing multilayers, optimized for the use with modern rotating anode X-ray generators. The multilayers are sputter deposited with a graded

Carsten Michaelsen; Joerg Wiesmann; Christian Hoffmann; A. Oehr; A. B. Storm; L. J. Seijbel

2004-01-01

227

Miniature diamond anvil pressure cell for single crystal x-ray diffraction studies  

Microsoft Academic Search

A new miniature gasketed diamond anvil high pressure cell has been constructed to perform optical and x-ray diffraction studies on single crystals under hydrostatic pressure. For x-ray studies the cell is mounted on a standard goniometer head which may be attached to either a standard precession camera or single crystal orienter taking advantage of counting methods. The pressure cell has

Leo Merrill; William A. Bassett

1974-01-01

228

Grain orientation mapping of passivated aluminum interconnect wires with X-ray micro-diffraction  

SciTech Connect

A micro x-ray diffraction facility is under development at the Advanced Light source. Spot sizes are typically about 1-{micro}m size generated by means of grazing incidence Kirkpatrick-Baez focusing mirrors. Photon energy is either white of energy range 6--14 keV or monochromatic generated from a pair of channel cut crystals. A Laue diffraction pattern from a single grain in passivated 2-{micro}m wide bamboo structured Aluminum interconnect line has been recorded. Acquisition times are of the order of a few seconds. The Laue pattern has allowed the determination of the crystallographic orientation of individual grains along the line length. The experimental and analysis procedures used are described, as is a grain orientation result. The future direction of this program is discussed in the context of strain measurements in the area of electromigration.

MacDowell, A.A.; Padmore, H.A.; Thompson, A.C. [Lawrence Berkeley National Lab., CA (United States); Chang, C.H.; Patel, J.R. [Lawrence Berkeley National Lab., CA (United States). Advanced Light Source Div.]|[Stanford Univ., CA (United States)

1998-06-01

229

Electrochemical discharge of nanocrystalline magnetite: structure analysis using X-ray diffraction and X-ray absorption spectroscopy.  

PubMed

Magnetite (Fe3O4) is an abundant, low cost, environmentally benign material with potential application in batteries. Recently, low temperature coprecipitation methods have enabled preparation of a series of nanocrystalline magnetite samples with a range of crystallite sizes. Electrochemical cells based on Li/Fe3O4 show a linear increase in capacity with decreasing crystallite size at voltages ?1.2 V where a 2× capacity improvement relative to commercial (26.2 nm) magnetite is observed. In this report, a combination of X-ray powder diffraction (XRD) and X-ray absorption spectroscopy (XAS) is used to measure magnetite structural changes occurring upon electrochemical reduction, with parent Fe3O4 crystallite size as a variable. Notably, XAS provides evidence of metallic iron formation at high levels of electrochemical reduction. PMID:24077019

Menard, Melissa C; Takeuchi, Kenneth J; Marschilok, Amy C; Takeuchi, Esther S

2013-10-01

230

(X-ray diffraction experiments with condenser matter)  

SciTech Connect

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

Coppens, P.

1990-01-01

231

X-ray Diffraction Crystal Calibration and Characterization  

SciTech Connect

National Security Technologies’ X-ray Laboratory is comprised of a multi-anode Manson type source and a Henke type source that incorporates a dual goniometer and XYZ translation stage. The first goniometer is used to isolate a particular spectral band. The Manson operates up to 10 kV and the Henke up to 20 kV. The Henke rotation stages and translation stages are automated. Procedures have been developed to characterize and calibrate various NIF diagnostics and their components. The diagnostics include X-ray cameras, gated imagers, streak cameras, and other X-ray imaging systems. Components that have been analyzed include filters, filter arrays, grazing incidence mirrors, and various crystals, both flat and curved. Recent efforts on the Henke system are aimed at characterizing and calibrating imaging crystals and curved crystals used as the major component of an X-ray spectrometer. The presentation will concentrate on these results. The work has been done at energies ranging from 3 keV to 16 keV. The major goal was to evaluate the performance quality of the crystal for its intended application. For the imaging crystals we measured the laser beam reflection offset from the X-ray beam and the reflectivity curves. For the curved spectrometer crystal, which was a natural crystal, resolving power was critical. It was first necessary to find sources of crystals that had sufficiently narrow reflectivity curves. It was then necessary to determine which crystals retained their resolving power after being thinned and glued to a curved substrate.

Michael J. Haugh; Richard Stewart; Nathan Kugland

2009-06-05

232

Ultrafast X-ray diffraction in liquid, solution and gas: present status and future prospects.  

PubMed

In recent years, the time-resolved X-ray diffraction technique has been established as an excellent tool for studying reaction dynamics and protein structural transitions with the aid of 100 ps X-ray pulses generated from third-generation synchrotrons. The forthcoming advent of the X-ray free-electron laser (XFEL) will bring a substantial improvement in pulse duration, photon flux and coherence of X-ray pulses, making time-resolved X-ray diffraction even more powerful. This technical breakthrough is envisioned to revolutionize the field of reaction dynamics associated with time-resolved diffraction methods. Examples of candidates for the first femtosecond X-ray diffraction experiments using highly coherent sub-100 fs pulses generated from XFELs are presented in this paper. They include the chemical reactions of small molecules in the gas and solution phases, solvation dynamics and protein structural transitions. In these potential experiments, ultrafast reaction dynamics and motions of coherent rovibrational wave packets will be monitored in real time. In addition, high photon flux and coherence of XFEL-generated X-ray pulses give the prospect of single-molecule diffraction experiments. PMID:20164650

Kim, Jeongho; Kim, Kyung Hwan; Lee, Jae Hyuk; Ihee, Hyotcherl

2010-02-18

233

Recent advances in continuum plasticity: phenomenological modeling and experimentation using X-ray diffraction  

NASA Astrophysics Data System (ADS)

This work explores the field of continuum plasticity from two fronts. On the theory side, we establish a complete specification of a phenomenological theory of plasticity for single crystals. The model serves as an alternative to the popular crystal plasticity formulation. Such a model has been previously proposed in the literature; the new contribution made here is the constitutive framework and resulting simulations. We calibrate the model to available data and use a simple numerical method to explore resulting predictions in plane strain boundary value problems. Results show promise for further investigation of the plasticity model. Conveniently, this theory comes with a corresponding experimental tool in X-ray diffraction. Recent advances in hardware technology at synchrotron sources have led to an increased use of the technique for studies of plasticity in the bulk of materials. The method has been successful in qualitative observations of material behavior, but its use in quantitative studies seeking to extract material properties is open for investigation. Therefore in the second component of the thesis several contributions are made to synchrotron X-ray diffraction experiments, in terms of method development as well as the quantitative reporting of constitutive parameters. In the area of method development, analytical tools are developed to determine the available precision of this type of experiment—a crucial aspect to determine if the method is to be used for quantitative studies. We also extract kinematic information relating to intragranular inhomogeneity which is not accessible with traditional methods of data analysis. In the area of constitutive parameter identification, we use the method to extract parameters corresponding to the proposed formulation of plasticity for a titanium alloy (HCP) which is continuously sampled by X-ray diffraction during uniaxial extension. These results and the lessons learned from the efforts constitute early reporting of the quantitative profitability of undertaking such a line of experimentation for the study of plastic deformation processes.

Edmiston, John Kearney

234

Determination of Densities from Chemical Composition and X-Ray Diffraction.  

National Technical Information Service (NTIS)

X-ray diffraction method applied to retained austenite measurements gives volume per cent results, whereas the same kind of measurement made by Moessbauer Effect gives iron percentages. To compare both results one needs to convert the volume % to weight %...

A. L. T. Azevedo

1980-01-01

235

Resonant (1s to 3d) X-Ray Bragg Diffraction by Transition-Metal Compounds.  

National Technical Information Service (NTIS)

Structure factors for Bragg diffraction of x-rays enhanced by electric quadrupole absorption are calculated for several configurations of the resonant ions found to exist in transition-metal compounds. The configurations include the spontaneous order (ful...

S. W. Lovesey K. S. Knight E. Balcar

2000-01-01

236

Powder x-ray diffraction patterns of energetic materials for use as reference standards.  

National Technical Information Service (NTIS)

This report lists eighteen quality powder x-ray diffraction patterns produced at Mound for various explosives of recent and current interest. In each case the best possible experimental pattern, obtained from the substance in question via automated diffra...

D. B. Sullenger J. S. Cantrell T. A. Beiter

1993-01-01

237

X-ray Diffraction Characterization of Suspended Structures for MEMS Applications.  

National Technical Information Service (NTIS)

Mechanical stress control is becoming one of the major challenges for the future of micro and nanotechnologies. Micro scanning X-ray diffraction is one of the promising techniques that allows stress characterization in such complex structures at sub micro...

P. Goudeau N. Tamura B. LAvelle S. Rigo T. Masri

2005-01-01

238

State-of-the-art and problems of X-ray diffraction analysis of biomacromolecules  

SciTech Connect

The state-of-the-art of X-ray diffraction studies of biomacromolecules is briefly characterized, and the challenge imposed by science is discussed. These studies are characterized by a wide scope and extensive use. This field of science is of great interest and is developed in many countries. The main purpose is to solve practical problems in medicine consisting in the design of drugs against various diseases. X-ray diffraction analysis of enzymes brought the pharmaceutical industry to a new level, thus allowing the rational design of drugs against formerly untreatable diseases. Modern X-ray diffraction studies of biomacromolecules laid the basis for a new science called structural biology. This method allows one to solve fundamental problems of physical chemistry for a new state of matter existing in living systems. Here, science poses numerous problems in analysis of X-ray diffraction data on biological macromolecules. Many of theses problems are in their infancy.

Andreeva, N. S. [Russian Academy of Sciences, Engelhardt Institute of Molecular Biology (Russian Federation)], E-mail: andreeva@eimb.ru

2006-12-15

239

State-of-the-art and problems of X-ray diffraction analysis of biomacromolecules  

NASA Astrophysics Data System (ADS)

The state-of-the-art of X-ray diffraction studies of biomacromolecules is briefly characterized, and the challenge imposed by science is discussed. These studies are characterized by a wide scope and extensive use. This field of science is of great interest and is developed in many countries. The main purpose is to solve practical problems in medicine consisting in the design of drugs against various diseases. X-ray diffraction analysis of enzymes brought the pharmaceutical industry to a new level, thus allowing the rational design of drugs against formerly untreatable diseases. Modern X-ray diffraction studies of biomacromolecules laid the basis for a new science called structural biology. This method allows one to solve fundamental problems of physical chemistry for a new state of matter existing in living systems. Here, science poses numerous problems in analysis of X-ray diffraction data on biological macromolecules. Many of theses problems are in their infancy.

Andreeva, N. S.

2006-12-01

240

Electrochemical in-situ reaction cell for X-ray scattering, diffraction and spectroscopy  

SciTech Connect

An electrochemical in-situ reaction cell for hard X-ray experiments with battery electrodes is described. Applications include the small angle scattering, diffraction, and near-edge spectroscopy of lithium manganese oxide electrodes.

Braun, Artur; Granlund, Eric; Cairns, Elton J.

2003-01-27

241

Carbon Fiber Morphology, II: Expanded Wide-Angle X-Ray Diffraction Studies of Carbon Fibers.  

National Technical Information Service (NTIS)

This report, describes the wide-angle x-ray diffraction studies and results on carbon and graphite fibers. Commercial PAN- and pitch-based carbon fibers spanning the generally available modulus range were examined. Crystal perfection, size, orientation, a...

D. P. Anderson

1991-01-01

242

Equation of state of solid neon from x-ray diffraction measurements to 110 GPa  

SciTech Connect

This paper briefly discusses the pressure-volume properties of condensed neon. X-ray diffraction techniques are used to determine solid neon equation of state and crystal structure. 16 refs., 2 figs. (LSP)

Hemley, R.J.; Jephcoat, A.P.; Zha, C.S.; Mao, H.K.; Finger, L.W.; Cox, D.E.

1987-01-01

243

Qualitative Mineralogical Characterization of the Sinter by X-Ray Diffraction.  

National Technical Information Service (NTIS)

This paper aims the qualitative mineralogical characterization of sinters and raw materials employed on its fabrication, via X-ray diffraction technique. Thus, sample with constant coke breeze content and variable contents of sand, limestone, dunite and d...

M. C. Greca L. R. V. Pietroluongo S. V. Baliza E. A. Costa Pereira

1987-01-01

244

In situ X-ray diffraction of prototype sodium metal halide cells: Time and space electrochemical profiling  

Microsoft Academic Search

The feasibility of using energy dispersive X-ray diffraction to characterize full size battery cells is demonstrated by unprecedented in situ measurements of the electrochemical processes taking place inside high temperature sodium metal halide (Na\\/MCl2, M=Ni and\\/or Fe) cells during charge\\/discharge cycling. Diffraction data provide phase information either via line scans across the 5cm wide cells or via fixed location scans

Job Rijssenbeek; Yan Gao; Zhong Zhong; Mark Croft; Najeh Jisrawi; Alexander Ignatov; Thomas Tsakalakos

2010-01-01

245

Method for improve x-ray diffraction determinations of residual stress in nickel-base alloys  

DOEpatents

A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys which comprises covering part of a predetermined area of the surface of a nickel-base alloy with a dispersion, exposing the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample.

Berman, Robert M. (Pittsburgh, PA); Cohen, Isadore (Pittsburgh, PA)

1990-01-01

246

Energy dispersive X-ray diffraction to identify explosive substances: Spectra analysis procedure optimization  

Microsoft Academic Search

To detect the presence of explosives in packages, automated systems are required. Energy dispersive X-ray diffraction (EDXRD) represents a powerful non-invasive tool providing information on the atomic structure of samples. In this paper, EDXRD is investigated as a suitable technique for explosive detection and identification. To this end, a database has been constructed, containing measured X-ray diffraction spectra of several

C. Crespy; P. Duvauchelle; V. Kaftandjian; F. Soulez; P. Ponard

2010-01-01

247

Modelling an Energy-Dispersive X-Ray Diffraction System for Drug Detection  

Microsoft Academic Search

A system for drug detection using X-ray diffraction is currently being developed by the DILAX collaboration. A simulation program for modelling the response of an energy-dispersive X-ray diffraction system has been developed, with the two-fold aim of selecting possible configurations prior to experimental tests and of generating data for statistical models for prediction of drug content. Simulated data showed a

Silvia Pani; Emily Cook; Julie Horrocks; Leah George; Sheila Hardwick; Robert Speller

2009-01-01

248

Structure of Si(001)-(4×3)In Surface Studied by X-Ray Photoelectron Diffraction  

Microsoft Academic Search

X-ray photoelectron diffraction (XPD) patterns of In 3d core levels have been measured for the Si(001)-(4×3)-In surface. An R factor analysis with single-scattering and multiple-scattering simulations of In 3d XPD patterns was performed for three structural models proposed so far. Only the model proposed by surface X-ray diffraction [Appl. Surf. Sci. 123\\/124, 104 (1998)] appeared to give a reasonably small

M. Shimomura; T. Nakamura; K.-S. Kim; T. Abukawa; J. Tani; S. Kono

1999-01-01

249

CO adsorption on Pt(1 1 0) investigated by X-ray photoelectron diffraction  

Microsoft Academic Search

The adsorption of CO on a Pt(110) surface was studied by X-ray photoelectron spectroscopy (XPS), X-ray photoelectron diffraction (XPD), and low energy electron diffraction (LEED). CO exposure during cooling the sample from 600 K to several final temperatures, Tf, resulted in CO layers of increasing coverage. For Tf>350 K, a disordered CO layer was obtained, characterized by a (1×1) LEED

M. Nowicki; A. Emundts; G. Pirug; H. P. Bonzel

2001-01-01

250

X-ray diffraction characterization of suspended structures forMEMS applications  

SciTech Connect

Mechanical stress control is becoming one of the major challenges for the future of micro and nanotechnologies. Micro scanning X-ray diffraction is one of the promising techniques that allows stress characterization in such complex structures at sub micron scales. Two types of MEMS structure have been studied: a bilayer cantilever composed of a gold film deposited on poly-silicon and a boron doped silicon bridge. X-ray diffraction results are discussed in view of numerical simulation experiments.

Goudeau, P.; Tamura, N.; Lavelle, B.; Rigo, S.; Masri, T.; Bosseboeuf, A.; Sarnet, T.; Petit, J.-A.; Desmarres, J.-M.

2005-09-15

251

Characterisation of microfocused beam for synchrotron powder diffraction using a new X-ray camera  

Microsoft Academic Search

The powder diffraction beamline I11, Diamond Light Source, is being continually upgraded as requirements of the user community evolve. Intensities of X-rays from the I11 in-vacuum electron undulator in the 3 GeV synchrotron fall off at higher energies. By focusing higher energy X-rays, we can overcome flux limitations, and open up new diffraction experiments. Here, we describe characterisation of microfocusing

C Thomas; J Potter; C C Tang; A R Lennie

2012-01-01

252

A method for automated determination of the crystal structures from X-ray powder diffraction data  

Microsoft Academic Search

An algorithm is proposed for determining the crystal structure of compounds. In the framework of this algorithm, X-ray powder\\u000a diffraction patterns are compared using a new similarity index. Unlike the indices traditionally employed in X-ray powder\\u000a diffraction analysis, the new similarity index can be applied even in the case of overlapping peaks and large differences\\u000a in unit cell parameters. The

D. W. M. Hofmann; L. N. Kuleshova

2006-01-01

253

Method for characterizing mask defects using image reconstruction from X-ray diffraction patterns  

Microsoft Academic Search

The invention applies techniques for image reconstruction from X-ray diffraction patterns on the three-dimensional imaging of defects in EUVL multilayer films. The reconstructed image gives information about the out-of-plane position and the diffraction strength of the defect. The positional information can be used to select the correct defect repair technique. This invention enables the fabrication of defect-free (since repaired) X-ray

Hau-Riege; Stefan Peter

2007-01-01

254

Imaging surface acoustic waves on GaAs by X-ray diffraction techniques  

Microsoft Academic Search

Surface acoustic waves (SAWs) are excited on the GaAs (001) surface by using interdigital transducers, designed for frequencies of up to 900 MHz. The emitted surface phonons with wave-lengths down to 3.5 ?m are visualized and characterized by combined x-ray diffraction techniques. By increasing the amplitude of the SAW, high resolution x-ray diffraction profiles show up to 12 phonon-induced satellite

W. Sauer; M. Streibl; T. H. Metzger; A. G. C. Haubrich; S. Manus; A. Wixforth; J. Peisl; A. Mazuelas; J. Haertwig; J. Baruchel

1999-01-01

255

Better Living Through Minerals: X-Ray Diffraction of Household Products  

NSDL National Science Digital Library

X-ray diffraction is a quick and valuable tool for identifying minerals. Minerals are an integral portion of our everyday life, in addition to composing our planet! They help bring electricity into our homes and remove our bathtub rings. In this lab, students analyze the X-ray diffraction patterns of three household cleansers, Ajax, White Magic, and Soft Scrub, in order to identify the abrasive minerals in each.

Dutrow, Barb

256

Cross-sectional texture of carbon fibres analysed by scanning microbeam X-ray diffraction  

Microsoft Academic Search

Scanning microbeam X-ray diffraction analysis of single carbon fibres allows the cross-sectional orientation distribution (texture) of the carbon layers to be determined, even when the fibre axis is oriented perpendicular to the X-ray beam (fibre geometry). The fibre is scanned across a microbeam with a diameter significantly smaller than the fibre diameter, and fibre diffraction patterns are recorded for every

Dieter Loidl; Martin Muller; Helga Lichtenegger; Herwig Peterlik; Erich Schmid

2001-01-01

257

Bragg diffraction using a 100ps 17.5 keV x-ray backlighter and the Bragg Diffraction Imager  

SciTech Connect

A new diagnostic for measuring Bragg diffraction from a laser-driven crystal using a 100ps 17.5 kV x-ray backlighter source is designed and tested successfully at the Omega EP laser facility on static Mo and Ta single crystal samples using a Mo Ka backlighter. The Bragg Diffraction Imager (BDI) consists of a heavily shielded enclosure and a precisely positioned beam block, attached to the main enclosure by an Aluminum arm. Image plate is used as the x-ray detector. The diffraction lines from Mo and Ta <222> planes are clearly detected with a high signal-to-noise using the 17.5 keV and 19.6 keV characteristic lines generated by a petawatt-driven Mo foil. This technique will be applied to shock and ramp-loaded single crystals on the Omega EP laser. Pulsed x-ray diffraction of shock- and ramp-compressed materials is an exciting new technique that can give insight into the dynamic behavior of materials at ultra-high pressure not achievable by any other means to date. X-ray diffraction can be used to determine not only the phase and compression of the lattice at high pressure, but by probing the lattice compression on a timescale equal to the 3D relaxation time of the material, information about dislocation mechanics, including dislocation multiplication rate and velocity, can also be derived. Both Bragg, or reflection, and Laue, or transmission, diffraction have been developed for shock-loaded low-Z crystalline structures such as Cu, Fe, and Si using nano-second scale low-energy implosion and He-{alpha} x-ray backlighters. However, higher-Z materials require higher x-ray probe energies to penetrate the samples, such as in Laue, or probe deep enough into the target, as in the case of Bragg diffraction. Petawatt laser-generated K{alpha} x-ray backlighters have been developed for use in high-energy radiography of dense targets and other HED applications requiring picosecond-scale burst of hard x-rays. While short pulse lasers are very efficient at producing high-energy x-rays, the characteristic x-rays produced in these thin foil targets are superimposed on a broad bremsstrahlung background and can easily saturate a detector if careful diagnostic shielding and experimental geometry are not implemented. A new diagnostic has been designed to measure Bragg diffraction from laser-driven crystal targets using characteristic x-rays from a short-pulse laser backlighter on the Omega EP laser. The Bragg Diffraction Imager, or BDI, is a TIM-mounted instrument consisting of a heavily shielded enclosure made from 3/8-inch thick Heavymet (W-Fe-Ni alloy) and a precisely positioned beam bock, attached to the main enclosure by an Aluminum arm. The beam block is made of 1-inch thick, Al-coated Heavymet and serves to block the x-rays directly from the petawatt backlight, while allowing the diffraction x-rays from the crystal to pass to the enclosure. A schematic of the BDI is shown in Fig. 1a. Image plates are used as the x-ray detector and are loaded through the top of the diagnostic in an Aluminum, light-tight cartridge. The front of the enclosure can be fitted with various filters to maximize the diffraction signal-to-noise.

Maddox, B R; Park, H; Hawreliak, J; Comley, A; Elsholz, A; Van Maren, R; Remington, B A; Wark, J

2010-05-13

258

Three-Dimensional Visualization of a Human Chromosome Using Coherent X-Ray Diffraction  

NASA Astrophysics Data System (ADS)

Coherent x-ray diffraction microscopy is a lensless phase-contrast imaging technique with high image contrast. Although electron tomography allows intensive study of the three-dimensional structure of cellular organelles, it has inherent difficulty with thick objects. X rays have the unique benefit of allowing noninvasive analysis of thicker objects and high spatial resolution. We observed an unstained human chromosome using coherent x-ray diffraction. The reconstructed images in two or three dimensions show an axial structure, which has not been observed under unstained conditions.

Nishino, Yoshinori; Takahashi, Yukio; Imamoto, Naoko; Ishikawa, Tetsuya; Maeshima, Kazuhiro

2009-01-01

259

Three-Dimensional Visualization of a Human Chromosome Using Coherent X-Ray Diffraction  

SciTech Connect

Coherent x-ray diffraction microscopy is a lensless phase-contrast imaging technique with high image contrast. Although electron tomography allows intensive study of the three-dimensional structure of cellular organelles, it has inherent difficulty with thick objects. X rays have the unique benefit of allowing noninvasive analysis of thicker objects and high spatial resolution. We observed an unstained human chromosome using coherent x-ray diffraction. The reconstructed images in two or three dimensions show an axial structure, which has not been observed under unstained conditions.

Nishino, Yoshinori; Ishikawa, Tetsuya [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Takahashi, Yukio [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Imamoto, Naoko; Maeshima, Kazuhiro [Cellular Dynamics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

2009-01-09

260

Structure-induced negatively skewed X-ray diffraction pattern of carbon onions  

NASA Astrophysics Data System (ADS)

The idea is discussed that a gradual change of intershell separation in carbon onions may introduce a negative skewness into the most intense X-ray diffraction band. As an example, the experimental X-ray diffraction pattern of carbon onions is analysed using a weighted Lorentzian X-ray profile broadening model for each intershell separation contributing to the profile. The dependence of the mean radius for carbon onion shells on the intershell spacing between the adjacent shells is derived from the model analysis. Comparison with the internal distribution of atomic density in carbon onions measured with high resolution transmission electron microscopy is discussed.

Siklitskaya, Alexandra; Yastrebov, Sergey; Smith, Roger

2013-10-01

261

Thermal and Electromigration-Induced Strains in Polycrystalline Films and Conductor Lines: X-ray Microbeam Measurements and Analysis  

SciTech Connect

X-ray microbeam measurements of thermal and electromigration-induced strains have been made at NSLS using white-beam energy dispersive x-ray diffraction, averaging over many grains, and at APS using white-beam Laue x-ray diffraction, from single grains. Grain-by-grain deviatoric strain measurements in Al films show wide variation in behavior for different grains in the films. Room temperature relaxation of residual strains was observed to occur at different rates for Al films with different bonding layers and substrates. X-ray microbeam measurements of strain development during electromigration for Cu and Al conductor lines show that strain gradients do not develop in the copper lines under conditions similar to those for which large strain gradients have been seen for Al lines.

Cargill, G. S. III; Moyer, L. E.; Wang, G.; Zhang, H. [Department of Materials Science and Engineering, Lehigh University, Bethlehem, PA 18015 (United States); Hu, C.-K. [IBM Research, Yorktown Hts., NY 10598 (United States); Yang, W.; Larson, B. C.; Ice, G. E. [Condensed Matter Sciences Division., Oak Ridge National Lab., Oak Ridge, TN 37831 (United States)

2006-02-07

262

A Grid Controlled X-Ray Diffraction Tube  

Microsoft Academic Search

A grid imposed between the filament and target of a demountable high vacuum type x-ray tube is modulated in synchronism with the full-wave rectified voltage impressed on the tube, by means of a square-wave generator. The grid potential varies in such a manner that the electron current flows only when the voltage is sufficiently high to excite the K series.

A. Eisenstein

1942-01-01

263

Analysis of carbon fibers and carbon composites by asymmetric X-ray diffraction technique  

Microsoft Academic Search

The effect of annealing on the microstructure of three sets of carbon fibers and their composites with a phenol-formaldehyde matrix was investigated by X-ray diffraction. An asymmetric diffraction geometry with parallel beam optics was used to get more information in comparison with conventional diffraction experiments. It was found that the microstructure of the samples is improved after annealing up to

L. Dobiášová; V. Starý; P. Glogar; V. Valvoda

1999-01-01

264

Diffraction rotation of the X-ray polarization plane  

Microsoft Academic Search

The article reports a theoretical and experimental study of polarization behavior in two-wave Laue diffraction occurring in diffraction rotation of the plane of polarization and manifested in the oscillation of the polarization ratio. The diffraction rotation is attributed to superposition of coherent differentially modulated amplitudes of diffracted waves. The polarization factor is found to be an oscillating function of crystal

I. P. Mikhailiuk; S. A. Kshevetskii; M. V. Ostapovich; V. P. Shafraniuk

1977-01-01

265

Relative intensity of the K?5 X-ray line  

NASA Astrophysics Data System (ADS)

The relative intensity of the K?5 (K-MIV,V) X-ray line as a function of the atomic number of the emitting elements is very strongly enhanced around Z = 24 (chromium) relative to predictions of the single-particle model for this electric dipole (El) forbidden transition. The enhancement is attributed to solid state or chemical effects. The K?5 transition can be El-allowed because in chemical compounds the outermost 3d level forms the valence shells, while in metals it becomes a broad band. The intensity of this line can therefore vary with the chemical state. We have determined the K?5/K?1 intensity ratio that results from proton impact on Ca, Ti and Cr, and we have collected the experimental data available in the literature. The influence of the sharp increase in the K?5 intensity on the K?/K? intensity ratio and on X-ray analytical methods (e.g. proton induced X-ray emission, electron probe microanalysis, etc.) is discussed.

Török, I.; Papp, T.; Pálinkás, J.; Budnar, M.; Mühleisen, A.; Kawai, J.; Campbell, J. L.

1996-06-01

266

Extended x-ray absorption fine structure, x-ray diffraction and reverse Monte Carlo studies of an amorphous Ga50Se50 alloy produced by mechanical alloying  

Microsoft Academic Search

The local atomic order of an amorphous Ga50Se50 alloy produced by mechanical alloying (MA) was studied by the extended x-ray absorption fine structure (EXAFS) and x-ray diffraction (XRD) techniques and by reverse Monte Carlo (RMC) simulations of its total x-ray structure factor. The coordination numbers and interatomic distances for the first neighbours were determined by means of EXAFS analysis and

K D Machado; J C de Lima; C E M Campos; T A Grandi

2004-01-01

267

Human Interleukin4 and Variant R88Q: Phasing X-ray Diffraction Data by Molecular Replacement Using X-ray and Nuclear Magnetic Resonance Models  

Microsoft Academic Search

The structure of recombinant human interleukin-4 (hIL-4) as been determined by both NMR and X-ray diffraction methods in several laboratories, including ours. The X-ray and NMR structures were successfully applied for solving the X-ray crystal structure by molecular replacement. Due to the small size of the hIL-4 molecule (129 residues) and its lack of structural diversity (4-helix bundle), this task

Thomas Müller; Frank Oehlenschläger; Manfred Buehner

1995-01-01

268

Extended x-ray-absorption fine-structure study of the annealing effect on glassy Pd76B24: Comparison with x-ray diffraction and modeling results  

Microsoft Academic Search

X-ray absorption spectra at the Pd K edge were obtained on as-quenched and annealed Pd76B24 up to the onset of polymorphous crystallization. Nearest-neighbors extended x-ray-absorption fine-structure (EXAFS) data were compared with previously reported x-ray diffraction data. For the first time we show here that in metallic glasses the envelope changes of first-shell radial distribution function accounts for experimental EXAFS data.

Giorgio Cocco; Stefano Enzo; Antonella Balerna; Settimio Mobilio; Jean Marie Dubois

1987-01-01

269

Complemenatary X-ray diffraction and X-ray reflectivity studies on SiGe and SiGe(C) heterostructures  

Microsoft Academic Search

High-resolution X-ray diffraction (XRD) and X-ray reflectivity (XRR) measurements were performed and evaluated to study the structural properties of various SiGe\\/Si and SiGe(C)\\/Si heterostructures, respectively. The main purpose of the present study was to combine the complementary information content of both X-ray scattering techniques to obtain a sample model that describes both sets of data sufficiently. One main advantage of

J. F. Woitok

2002-01-01

270

Direct measurement of the x-ray refractive index by Fresnel diffraction at a transparent edge.  

PubMed

We demonstrate the feasibility of measuring x-ray refractive indices by transparent edge diffraction without recourse to the Kramers-Kronig relations. The method requires a coherent x-ray source, a transparent sample with a straight edge, and a high resolution x-ray detector. Here, we use the aluminum K? radiation originating from a laser-produced plasma to coherently illuminate the edge of thin aluminum and beryllium foils. The resulting diffraction patterns are recorded with an x-ray CCD camera. From least-squares fits of Fresnel diffraction modeling to the measured data we determine the refractive index of Al and Be at the wavelength of the Al K? radiation (0.834 nm, 1.49 keV). PMID:23632552

Gayer, C W; Hemmers, D; Stelzmann, C; Pretzler, G

2013-05-01

271

Stoichiometry optimization of homoepitaxial oxide thin films using x-ray diffraction  

SciTech Connect

Homoepitaxial SrTiO{sub 3} thin films grown by molecular beam epitaxy are analyzed using high-resolution x-ray diffraction and transmission electron microscopy. Measured 00L x-ray scans from stoichiometric and nonstoichiometric films are compared with calculations that account for the effects of film thickness, lattice parameter, fractional site occupancy, and an offset between film and substrate at the interface. It is found that thickness fringes, commonly observed around Bragg reflections even in stoichiometric homoepitaxial SrTiO{sub 3} films, arise from a film/substrate interface offset. Transmission electron microscopy studies confirm the presence of strain at those homoepitaxial interfaces that show an offset in x-ray diffraction. The consequences for stoichiometry optimization of homoepitaxial films using high-resolution x-ray diffraction and the quality of regrown oxide interfaces are discussed.

LeBeau, James M.; Engel-Herbert, Roman; Jalan, Bharat; Cagnon, Joeel; Moetakef, Pouya; Stemmer, Susanne [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States); Stephenson, G. Brian [Materials Science Division and Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2009-10-05

272

Stoichiometry optimization of homoepitaxial oxide thin films using x-ray diffraction.  

SciTech Connect

Homoepitaxial SrTiO{sub 3} thin films grown by molecular beam epitaxy are analyzed using high-resolution x-ray diffraction and transmission electron microscopy. Measured 00L x-ray scans from stoichiometric and nonstoichiometric films are compared with calculations that account for the effects of film thickness, lattice parameter, fractional site occupancy, and an offset between film and substrate at the interface. It is found that thickness fringes, commonly observed around Bragg reflections even in stoichiometric homoepitaxial SrTiO{sub 3} films, arise from a film/substrate interface offset. Transmission electron microscopy studies confirm the presence of strain at those homoepitaxial interfaces that show an offset in x-ray diffraction. The consequences for stoichiometry optimization of homoepitaxial films using high-resolution x-ray diffraction and the quality of regrown oxide interfaces are discussed.

LeBeau, J. M.; Engel-Herbert, R.; Jalan, B.; Cagnon, J.; Moetakef, P.; Stemmer, S.; Stephenson, G. B.; Materials Science Division; Univ. of California at Santa Barbara

2009-10-05

273

X-ray Bragg diffraction profiles from unstrained layered single-crystal structures: theoretical considerations, simulation and reconstruction using phase-retrieval X-ray diffractometry  

Microsoft Academic Search

The X-ray Bragg diffraction intensity profile for a model strain-compensated single-crystal structure consisting of a thin alloy layer grown on a thick substrate is derived using a Laplace transform interpretation of the kinematical approximation of X-ray diffraction theory, assuming a step-like attenuation depth-profile. The effects of the model physical parameters on the measurable Bragg diffraction intensity profile are discussed. The

A. Y. Nikulin; R. Steinfeld

2004-01-01

274

First results from a next-generation off-plane X-ray diffraction grating  

NASA Astrophysics Data System (ADS)

Future NASA X-ray spectroscopy missions will require high throughput, high resolving power grating spectrometers. Off-plane reflection gratings are capable of meeting the performance requirements needed to realize the scientific goals of these missions. We have identified a novel grating fabrication method that utilizes common lithographic and microfabrication techniques to produce the high fidelity groove profile necessary to achieve this performance. Application of this process has produced an initial pre-master that exhibits a radial (variable line spacing along the groove dimension), high density (> 6000 grooves/mm), laminar profile. This pre-master has been tested for diffraction efficiency at the BESSY II synchrotron light facility and diffracts up to 55 % of incident light into usable spectral orders. Furthermore, tests of spectral resolving power show that these gratings are capable of obtaining resolving powers well above 1300 ( ?/? ?) with limitations due to the test apparatus, not the gratings. Obtaining these results has provided confidence that this fabrication process is capable of producing off-plane reflection gratings for the next generation of X-ray observatories.

McEntaffer, Randall; DeRoo, Casey; Schultz, Ted; Gantner, Brennan; Tutt, James; Holland, Andrew; O'Dell, Stephen; Gaskin, Jessica; Kolodziejczak, Jeffrey; Zhang, William W.; Chan, Kai-Wing; Biskach, Michael; McClelland, Ryan; Iazikov, Dmitri; Wang, Xinpeng; Koecher, Larry

2013-08-01

275

Dynamical x-ray diffraction from an icosahedral Al-Pd-Mn quasicrystal  

SciTech Connect

Primary extinction effects in diffraction from single grains of Al-Pd- Mn, and presumably many other FCI alloys, may be significant and should be corrected for prior to use of diffraction data in structural determinations. Probes based on dynamical diffraction effects, such as x-ray standing wave fluorescence, multiple beam interference, and x-ray transmission topographs, may now be used to study the bulk and surface structure of some quasicrystals. The observation of dynamical diffraction from icosahedral Al-Pd-Mn is a striking confirmation of the fact that quasicrystals can present a degree of structural perfection comparable to that found in the best periodic intermetallic crystals.

Kycia, S.

1996-04-23

276

Advanced x-ray stress analysis method for a single crystal using different diffraction plane families  

NASA Astrophysics Data System (ADS)

Generalized formula of the x-ray stress analysis for a single crystal with unknown stress-free lattice parameter was proposed. This method enables us to evaluate the plane stress states with any combination of diffraction planes. We can choose and combine the appropriate x-ray sources and diffraction plane families, depending on the sample orientation and the apparatus, whenever diffraction condition is satisfied. The analysis of plane stress distributions in an iron single crystal was demonstrated combining with the diffraction data for Fe{211} and Fe{310} plane families.

Imafuku, Muneyuki; Suzuki, Hiroshi; Sueyoshi, Kazuyuki; Akita, Koichi; Ohya, Shin-Ichi

2008-06-01

277

Advanced x-ray stress analysis method for a single crystal using different diffraction plane families  

SciTech Connect

Generalized formula of the x-ray stress analysis for a single crystal with unknown stress-free lattice parameter was proposed. This method enables us to evaluate the plane stress states with any combination of diffraction planes. We can choose and combine the appropriate x-ray sources and diffraction plane families, depending on the sample orientation and the apparatus, whenever diffraction condition is satisfied. The analysis of plane stress distributions in an iron single crystal was demonstrated combining with the diffraction data for Fe{l_brace}211{r_brace} and Fe{l_brace}310{r_brace} plane families.

Imafuku, Muneyuki [Materials Characterization Center, Nippon Steel Technoresearch Corporation, Futtsu, Chiba 293-0011 (Japan); Suzuki, Hiroshi [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Naka-gun, Ibaraki 319-1195 (Japan); Sueyoshi, Kazuyuki; Akita, Koichi; Ohya, Shin-ichi [Department of Mechanical Systems Engineering, Musashi Institute of Technology, Setagaya, Tokyo 158-8557 (Japan)

2008-06-09

278

Versatile wide angle diffraction setup for simultaneous wide and small angle x-ray scattering measurements with synchrotron radiation  

SciTech Connect

Here we present a novel, simple, and versatile experimental setup aimed to perform wide angle x-ray scattering (WAXS) measurements alone or in simultaneous combination with small angle x-ray scattering measurements. The design of the WAXS goniometer allows one to obtain high resolution diffraction patterns in a broad angular range. The setup can incorporate a hot stage in order to evaluate temperature resolved experiments. The performance of the equipment has been verified in the BM16 beam line of the European Synchrotron Radiation Facility with different well known samples such as alumina, isotropic film of high density polyethylene (HDPE), and oriented HPDE fiber.

Rueda, D.R.; Garcia-Gutierrez, M.C.; Nogales, A.; Capitan, M.J.; Ezquerra, T.A.; Labrador, A.; Fraga, E.; Beltran, D.; Juanhuix, J.; Herranz, J.F.; Bordas, J. [Instituto de Estructura de la Materia, CSIC, Serrano 119, 28006 Madrid (Spain); LLS, BM16-ESRF, 6 rue Jules Horowitz, BP220, 38043 Grenoble (France)

2006-03-15

279

Destructive interferences between diffuse scatterings due to disorder and displacive modulation (X-ray ``white line  

Microsoft Academic Search

In the solid solutions of charge transfer salts of the TTF-TCNQ family, a new diffraction effect is observed. The X-ray patterns of such materials show a broad diffuse scattering on which fine ``white'' diffuse lines at {Q} + 2 {k}_f are observed, whereas at {Q} - 2 {k}_f the diffuse scattering has the usual aspect. We propose a simple interpretation

S. Ravy; J. P. Pouget; R. Comes

1992-01-01

280

An attempt to overcome diffraction limit in detectors for x-ray nanotomography  

NASA Astrophysics Data System (ADS)

In synchrotron set-ups with a parallel x-ray beam, the spatial resolution is fully defined by the x-ray camera performance. This is also true in some laboratory x-ray imaging and CT instruments with an object position close to the detector. Fiber optic coupling does not allow camera resolutions reaching micron and submicron range, while cameras with lens coupling demonstrate resolutions close to diffraction limit, i.e. around 0.5 microns. Considering the conversion of x-rays to light in scintillator materials as a type of fluorescence under certain excitation, it should be possible to implement a method similar to Stochastic Optical Reconstruction Microscopy (STORM) in fluorescent microscopy to overcome diffraction limit in detector resolution. Our idea to overcome diffraction limit in such detectors is as follows. Every x-ray photon produces a significant amount of optical photons emitted from one particular point inside the scintillator. A fraction of the emitted optical photons is collected by a lens and hits the detector with a spread defined by the diffraction limit. Comparing the signal spread from every individual x-ray photon with the expected pre-calculated spread function, one can find the exact positions of primary x-ray photon. Using such exact positions to create images instead of collecting all incoming optical photons allows tracking exact positions of all original emitting points of x-ray photons without influence of optical diffraction limit. It can create images with a spatial resolution significantly better than what can be achieved in conventional diffraction limited optical acquisition.

Sasov, A.

2012-10-01

281

Quality experimental and calculated powder x-ray diffraction.  

National Technical Information Service (NTIS)

For several years, we have submitted quality powder XRD patterns to the International Centre for Diffraction Data for inclusion as reference standards in their Powder Diffraction File. The procedure followed is described; examples used are (beta)-UH(sub 3...

D. B. Sullenger J. S. Cantrell T. A. Beiter D. W. Tomlin

1996-01-01

282

Spectral characteristics of plane multilayer amplitude diffraction gratings for the soft x-ray range  

NASA Astrophysics Data System (ADS)

Several spectral characteristics of plane multilayer amplitude molybdenum—silicon diffraction gratings (1000 and 2000 lines mm-1), fabricated by electron-beam lithography, were determined with a broadband laser-plasma source of soft x-rays. The gratings, with the multilayer structure period 11.5 nm, were investigated at near-normal incidence and at an angle of incidence of 36o in a quasi-stigmatic spectrograph system with moderate dispersion. The spectral profile of resonant reflection by the gratings was determined in the first and second interference orders of the multilayer structure for different angles of incidence. The line spectrum of multiply charged F(V) and F(VI) ions was recorded in the 16.0-18.5 nm range by means of these multilayer gratings and the resolving power of the gratings was estimated.

Troussel, P.; Bac, S.; Kolachevsky, Nikolai N.; Mitropol'skii, M. M.; Ragozin, Evgenii N.

1996-10-01

283

Comparison of a CCD and an APS for soft X-ray diffraction  

NASA Astrophysics Data System (ADS)

We compare a new CMOS Active Pixel Sensor (APS) to a Princeton Instruments PIXIS-XO: 2048B Charge Coupled Device (CCD) with soft X-rays tested in a synchrotron beam line at the Diamond Light Source (DLS). Despite CCDs being established in the field of scientific imaging, APS are an innovative technology that offers advantages over CCDs. These include faster readout, higher operational temperature, in-pixel electronics for advanced image processing and reduced manufacturing cost. The APS employed was the Vanilla sensor designed by the MI3 collaboration and funded by an RCUK Basic technology grant. This sensor has 520 x 520 square pixels, of size 25 ?m on each side. The sensor can operate at a full frame readout of up to 20 Hz. The sensor had been back-thinned, to the epitaxial layer. This was the first time that a back-thinned APS had been demonstrated at a beam line at DLS. In the synchrotron experiment soft X-rays with an energy of approximately 708 eV were used to produce a diffraction pattern from a permalloy sample. The pattern was imaged at a range of integration times with both sensors. The CCD had to be operated at a temperature of -55°C whereas the Vanilla was operated over a temperature range from 20°C to -10°C. We show that the APS detector can operate with frame rates up to two hundred times faster than the CCD, without excessive degradation of image quality. The signal to noise of the APS is shown to be the same as that of the CCD at identical integration times and the response is shown to be linear, with no charge blooming effects. The experiment has allowed a direct comparison of back thinned APS and CCDs in a real soft x-ray synchrotron experiment.

Stewart, Graeme; Bates, R.; Blue, A.; Clark, A.; Dhesi, S. S.; Maneuski, D.; Marchal, J.; Steadman, P.; Tartoni, N.; Turchetta, R.

2011-12-01

284

X-ray diffraction from levitated liquid yttrium oxide  

SciTech Connect

The authors report the first measurements of the structure factor, S(Q), and radial distribution function, G(r), of yttrium oxide in the normal and supercooled liquid states in the temperature range 2,500--3,100 K. Measurements were obtained by synchrotron X-ray scattering on levitated, laser-heated liquid specimens. At temperatures far in excess of the melting point, the first and second coordination shells begin to merge, indicative of increased ionicity in the liquid. As the temperature is lowered into the supercooled region, there is substantial sharpening and strengthening in the first peaks in both S(Q) and G(r). Supercooling causes a decrease in the first shell coordination and Q values together with an increase in the Y-O interionic distance.

Krishnan, S. [Containerless Research, Inc., Evanston, IL (United States); Ansell, S.; Price, D.L. [Argonne National Lab., IL (United States)

1998-07-01

285

X-ray diffraction and electron microscopy studies of frozen erythrocyte membrane preparations.  

PubMed

Well-defined X-ray diffraction patterns have been recorded from erythrocyte membranes in the frozen state. At -40 degrees C, lamellar periodicities range from 19 to 95 nm depending on the glycerol content (0--40%, respectively). Freeze-fracture electon micrographs of samples frozen in two stages to approximate to the diffraction conditions show ice formation external to membrane stacks. The membrane stacks have periodicities of the same order of magnitude as those obtained by X-ray diffraction. PMID:7397175

Rzepecki, L M; Berriman, J; Finean, J B

1980-07-16

286

Polarity determination of wurtzite-type crystals using hard x-ray photoelectron diffraction  

Microsoft Academic Search

The surface structure of a single-crystal ZnO wafer was studied by angle-resolved x-ray photoelectron spectroscopy (ARXPS) using synchrotron radiation. As a result, well-defined x-ray photoelectron diffraction (XPD) patterns were obtained for the (0001) and (0001¯) polar surfaces using the photoemission from the Zn 2p3\\/2 and O 1s core levels. The XPD patterns were indexed assuming forward scattering of photoelectrons by

Jesse R. Williams; Masaaki Kobata; Igor Pis; Eiji Ikenaga; Takeharu Sugiyama; Keisuke Kobayashi; Naoki Ohashi

2011-01-01

287

Deep X-Ray Lithography in the Fabrication Process of a 3D Diffractive Optical Element  

NASA Astrophysics Data System (ADS)

We present first results of the fabrication process of a diffractive optical element (DOE) using deep X-ray lithography. The DOE forms the core of our proposed fast parallel-processing infrared Fourier transform interferometer (FPP FTIR) that works without moving parts and may allow instantaneous spectral analysis only limited by detector bandwidth. Design and specifications of the DOE are discussed. A fabrication process including deep X-ray lithography (DXRL) on stepped substrates is introduced.

Heussler, S. P.; Moser, H. O.; Quan, C. G.; Tay, C. J.; Moeller, K. D.; Bahou, M.; Jian, L. K.

2007-01-01

288

Computed tomography of x-ray index of refraction using the diffraction enhanced imaging method  

Microsoft Academic Search

Diffraction enhanced imaging (DEI) is a new, synchrotron-based, x-ray radiography method that uses monochromatic, fan-shaped beams, with an analyser crystal positioned between the subject and the detector. The analyser allows the detection of only those x-rays transmitted by the subject that fall into the acceptance angle (central part of the rocking curve) of the monochromator\\/analyser system. As shown by Chapman

F. A. Dilmanian; Z. Zhong; B. Ren; X. Y. Wu; L. D. Chapman; I. Orion; W. C. Thomlinson

2000-01-01

289

Transient X-ray Diffraction and Its Application to Materials Science and Direct Drive Imprinting  

Microsoft Academic Search

Transient x-ray diffraction utilizing a laser-plasma x-ray source has been applied to a variety of problems including shock wave analysis of dynamic materials properties. The method has also been applied to the study of the early stages of the imprinting of non uniformities in direct drive laser fusion. Experiments will be reported that study such materials properties as plastic stress

A. A. Hauer; J. S. Wark; J. A. Cobble; R. Kopp; G. A. Kyrala; R. Springer; D. Kalantar; B. Remington; B. Failor; T. Bohley; M. Meyers

1997-01-01

290

Proposal of a novel Diffraction Enhanced Imaging setup based on polycapillary X-ray optics  

Microsoft Academic Search

Diffraction Enhanced Imaging (DEI) is a recent technique developed to improve the diagnostic capabilities of radiography by exploiting coherently scattered X-rays to generate images that provide higher contrast than conventional transmission imaging. Earlier experiments, carried out in the synchrotron environment using a mechanical parallel-hole collimator coupled to a 2D X-ray imager, confirmed the potential of this technique in mammography. The

Andrea Castoldi; C. Ozkan; C. Guazzoni; A. Bjeoumikhov; J. Griffiths; G. Royle; R. Hartmann

2008-01-01

291

X-ray diffraction and impedance spectroscopy studies of lithium manganese oxide spinel  

Microsoft Academic Search

Phase transition in lithium manganese oxide spinel synthesized by sol–gel technique and in samples prepared from commercially available powders of LiMn2O4 (Alfa-Aesar and Sigma–Aldrich) was investigated. In addition to the standard impedance measurements and the X-ray diffraction in Bragg–Brentano geometry, simultaneous measurements of impedance spectrum and X-ray pattern in non-focusing geometry were performed in the temperature range between ?25 and

M. Kope?; D. Lisovytskiy; M. Marzantowicz; J. R. Dygas; F. Krok; Z. Kaszkur; J. Pielaszek

2006-01-01

292

Development of a prototype pipework scanning system based upon energy dispersive X-ray diffraction (EDXRD)  

Microsoft Academic Search

A prototype pipework scanning system based upon energy dispersive X-ray diffraction (EDXRD) has been produced, for which system development and preliminary results are presented here. This apparatus has been developed from experience with 2D and 3D bench-top EDXRD systems and comprises a conventional industrial X-ray tube coupled to a bespoke design of tungsten collimators and compact CdTe detector. It is

D. J. Garrity; A. J. De Rosa; D. A. Bradley; S. E. Jarman; P. M. Jenneson; S. M. Vincent

2010-01-01

293

The first x-ray diffraction station at Beijing Synchrotron Radiation Laboratory, BEPC  

Microsoft Academic Search

The first x-ray diffraction experimental station at Beijing Synchrotron Radiation Laboratory has been available for synchrotron radiation users in research. The station is located on the back-end of 4B9A, a beamline from a bending magnet. When the storage ring of BEPC operates in a dedicated mode (2.2 GeV), 4B9A provides a focused monochromatic x ray in between 4 and 12

D. W. Wang; J. F. Liu; Y. C. Zhao; Y. L. Yang; D. S. Liu; D. C. Xian

1992-01-01

294

Quantitative determination of mineral composition by powder x-ray diffraction  

DOEpatents

An external standard intensity ratio method is used for quantitatively determining mineralogic compositions of samples by x-ray diffraction. The method uses ratios of x-ray intensity peaks from a single run. Constants are previously determined for each mineral which is to be quantitatively measured. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of a reference mineral contained in the sample are used to calculate sample composition.

Pawloski, G.A.

1984-08-10

295

New software to model energy dispersive X-ray diffraction in polycrystalline materials  

Microsoft Academic Search

Detection of illicit materials, such as explosives or drugs, within mixed samples is a major issue, both for general security and as part of forensic analyses. In this paper, we describe a new code simulating energy dispersive X-ray diffraction patterns in polycrystalline materials. This program, SinFullscat, models diffraction of any object in any diffractometer system taking all physical phenomena, including

B. Ghammraoui; J. Tabary; S. Pouget; C. Paulus; V. Moulin; L. Verger; Ph. Duvauchelle

296

X-ray photoelectron diffraction for the HgCdTe (111) surface  

Microsoft Academic Search

The surface polarity of a mercury cadmium telluride (MCT) (111) crystal surface has been determined by x-ray photoelectron diffraction (XPD). Emission from the core levels of Hg, Cd, and Te gave reproducible photoelectron diffraction patterns with considerable fine structure. Comparisons between experiment and single scattering cluster calculations via R factors very well distinguished the different kinds of lattice site of

G. S. Herman; D. J. Friedman; T. T. Tran; C. S. Fadley; G. Granozzi; G. A. Rizzi; J. Osterwalder; S. Bernadi

1991-01-01

297

Studies of Surface and Thin Film Structures by X-Ray Photoelectron Diffraction  

Microsoft Academic Search

The knowledge of atomic structure in the surface region is essential to the comprehension of surface physical phenomena. In this thesis research, x-ray photoelectron diffraction and Auger electron diffraction (XPD) have been used to study a series of single crystal surface and thin film structures, ranging from simple fcc lattices to more complicated diamond and calcium fluorite structures. The systems

Jian Zhang

1994-01-01

298

Surfactant mediated heteroepitaxial growth of Ge Si(111) probed by X-ray photoelectron diffraction  

Microsoft Academic Search

X-ray photoelectron diffraction (XPD) is used as a tool to investigate the growth of Ge on Si(111) with and without surfactant (Sb) mediation. Structural information is extracted directly from the forward scattering maxima of recorded photoelectron diffraction patterns. The result of a quantitative analysis of the patterns taken for Ge layers of different coverage are used for a structural growth

S. Dreiner; C. Westphal; F. Sökeland; H. Zacharias

1998-01-01

299

Dynamical theory for diffractive x-ray imaging of one-dimensional periodic objects  

SciTech Connect

A dynamical theory for diffractive x-ray imaging of one-dimensional periodic objects is derived by solving the Helmholtz equation in the parabolic approximation using the coupled-wave theory. A method to account for volume-diffraction effects, based on propagating backwards the eigenmodes of the microfluidic array, is demonstrated for a colloidal suspension in confinement.

Nygaard, K.; Satapathy, D. K.; Bunk, O.; David, C. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Pfeiffer, F. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Veen, J. F. van der [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); ETH Zuerich, CH-8093 Zuerich (Switzerland)

2008-05-26

300

Titration of a Solid Acid Monitored by X-Ray Diffraction  

ERIC Educational Resources Information Center

|An experiment is described to introduce students to an important class of solid-state reactions while reinforcing concepts of titration by using a pH meter and a powder X-ray diffractometer. The experiment was successful in teaching students the abstract concepts of solid-state structure and diffraction by applying the diffraction concepts…

Dungey, Keenan E.; Epstein, Paul

2007-01-01

301

Analytic theory of soft x-ray diffraction by lamellar multilayer gratings  

Microsoft Academic Search

An analytic theory describing soft x-ray diffraction by Lamellar Multilayer Gratings (LMG) has been developed. The theory is derived from a coupled waves approach for LMGs operating in the single-order regime, where an incident plane wave can only excite a single diffraction order. The results from calculations based on these very simple analytic expressions are demonstrated to be in excellent

I. V. Kozhevnikov; R. van der Meer; H. M. J. Bastiaens; K.-J. Boller; F. Bijkerk

2011-01-01

302

In situ X-ray diffraction investigation of thermal decomposition of wood cellulose  

Microsoft Academic Search

The kinetics of thermal decomposition of crystalline cellulose in spruce wood (Picea abies [L.] Karst.) was studied by in situ X-ray diffraction using synchrotron radiation. Fiber diffraction patterns resulting from the crystal lattice of native cellulose arranged in oriented microfibrils were collected as a function of heat treatment time for various temperatures from 300 to 360°C. Sample heating was performed

Gerald A. Zickler; Wolfgang Wagermaier; Sérgio S. Funari; Manfred Burghammer; Oskar Paris

2007-01-01

303

Two-dimensional measurement of focused hard X-ray beam profile using coherent X-ray diffraction of isolated nanoparticle  

NASA Astrophysics Data System (ADS)

A method for evaluating the two-dimensional photon density distribution in focused hard X-ray beams is proposed and demonstrated in a synchrotron experiment at SPring-8. A synchrotron X-ray beam of 11.8 keV is focused to a ˜1?m spot by Kirkpatrick-Baez mirrors. The two-dimensional intensity distribution of the focused beam is derived by monitoring the forward diffracted intensity from an isolated silver nanocube with an edge length of ˜150nm positioned in the beam waist, which is two-dimensionally scanned. Furthermore, the photon density of X-rays illuminated onto the nanocube is estimated by utilizing coherent X-ray diffraction microscopy. This method is useful for evaluating the photon density distribution of hard X-ray beams focused to a spot size of less than a few micrometers.

Takahashi, Yukio; Kubo, Hideto; Tsutsumi, Ryosuke; Sakaki, Shigeyuki; Zettsu, Nobuyuki; Nishino, Yoshinori; Ishikawa, Tetsuya; Yamauchi, Kazuto

2010-05-01

304

Dynamical x-ray diffraction from nonuniform crystalline films: Application to x-ray rocking curve analysis  

SciTech Connect

A dynamical model for the general case of Bragg x-ray diffraction from arbitrarily thick nonuniform crystalline films is presented. The model incorporates depth-dependent strain and a spherically symmetric Gaussian distribution of randomly displaced atoms and can be applied to the rocking curve analysis of ion-damaged single crystals and strained layer superlattices. The analysis of x-ray rocking curves using this model provides detailed strain and damage depth distributions for ion-implanted or MeV-ion-bombarded crystals and layer thickness, and lattice strain distributions for epitaxial layers and superlattices. The computation time using the dynamical model is comparable to that using a kinematical model. We also present detailed strain and damage depth distributions in MeV-ion-bombarded GaAs(100) crystals. The perpendicular strain at the sample surface, measured as a function of ion-beam dose (D), nuclear stopping power (S/sub n/), and electronic stopping power (S/sub e/) is shown to vary according to (1-kS/sub e/)DS/sub n/ and saturate at high doses.

Wie, C.R.; Tombrello, T.A.; Vreeland T. Jr.

1986-06-01

305

Structural characterization of SrLaMnRuO 6 by synchrotron X-ray powder diffraction and X-ray absorption spectroscopy  

Microsoft Academic Search

Single-phase polycrystalline powder samples of SrLaMnRuO6 were prepared by solid-state synthesis method and its crystal structure was studied using synchrotron X-ray diffraction and X-ray absorption spectroscopies. The Rietveld analysis of the room temperature synchrotron X-ray diffraction data shows that it has a double perovskite structure with disordered arrangements of Sr\\/La and Mn\\/Ru and adopts orthorhombic space group Pbnm [a=5.5004(3)Å, b=5.5445(3)Å,

Javaid Bashir; Rubina Shaheen; Muhammad Nasir Khan

2008-01-01

306

Quality experimental and calculated powder x-ray diffraction  

SciTech Connect

For several years, we have submitted quality powder XRD patterns to the International Centre for Diffraction Data for inclusion as reference standards in their Powder Diffraction File. The procedure followed is described; examples used are {beta}-UH{sub 3}, {alpha}- BaT{sub 2}, alpha-lithium disilicate ({alpha}-Li{sub 2}Si{sub 2}O{sub 5}), and 2,2`,4,4`,6,6`hexanitroazobenzene-III (HNAB-III).

Sullenger, D.B.; Cantrell, J.S.; Beiter, T.A.; Tomlin, D.W.

1996-08-01

307

X-ray powder diffraction patterns for certain beta-lactam, tetracycline and macrolide antibiotic drugs.  

PubMed

X-ray powder diffraction (XRD) data for eight beta-lactam viz., ampicillin sodium, ampicillin trihydrate, penicillin G procaine, benzathine penicillin, benzyl penicillin sodium, cefalexin, cefotaxime sodium and ceftriaxone sodium; three tetracyclines viz., doxycycline hydrochloride, oxytetracycline dihydrate and tetracycline hydrochloride; and two macrolide viz., azithromycin and erythromycin estolate antibiotic drugs were obtained using a powder diffractometer. The drugs were scanned from Bragg angles (2theta) of 10 degrees to 70 degrees. The obtained data were tabulated in terms of the lattice spacing (A) and relative line intensities (I/I(I)). This new information may be useful for identifying these drugs from confiscated materials, which has been frequently encountered in forensic laboratories. PMID:16038505

Thangadurai, S; Abraham, J T; Srivastava, A K; Moorthy, M Nataraja; Shukla, S K; Anjaneyulu, Y

2005-07-01

308

Investigation on the surface layer characteristics of shot peened titanium matrix composite utilizing X-ray diffraction  

Microsoft Academic Search

The surface layer characteristics of shot peened (TiB+TiC)\\/Ti–6Al–4V composite are investigated using X-ray diffraction line profile analysis. The structural breadth, domain sizes, microstrain and dislocation densities of the matrices and composite are obtained. The results show that the domain sizes are refined after shot peening, and the dislocation densities are increased sharply in the near surface layer, which result from

Lechun Xie; Chuanhai Jiang; Weijie Lu; Qiang Feng; Xueyan Wu

2011-01-01

309

Reconstructive colour X-ray diffraction imaging--a novel TEDDI imaging method.  

PubMed

Tomographic Energy-Dispersive Diffraction Imaging (TEDDI) enables a unique non-destructive mapping of the interior of bulk objects, exploiting the full range of X-ray signals (diffraction, fluorescence, scattering, background) recorded. By analogy to optical imaging, a wide variety of features (structure, composition, orientation, strain) dispersed in X-ray wavelengths can be extracted and colour-coded to aid interpretation. The ultimate aim of this approach is to realise real-time high-definition colour X-ray diffraction imaging, on the timescales of seconds, so that one will be able to 'look inside' optically opaque apparatus and unravel the space/time-evolution of the materials chemistry taking place. This will impact strongly on many fields of science but there are currently two barriers to this goal: speed of data acquisition (a 2D scan currently takes minutes to hours) and loss of image definition through spatial distortion of the X-ray sampling volume. Here we present a data-collection scenario and reconstruction routine which overcomes the latter barrier and which has been successfully applied to a phantom test object and to real materials systems such as a carbonating cement block. These procedures are immediately transferable to the promising technology of multi-energy-dispersive-detector-arrays which are planned to deliver the other breakthrough, that of one-two orders of magnitude improvement in data acquisition rates, that will be needed to realise real-time high-definition colour X-ray diffraction imaging. PMID:19684902

Lazzari, Olivier; Jacques, Simon; Sochi, Taha; Barnes, Paul

2009-06-26

310

Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers.  

SciTech Connect

The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar{reg_sign} or Twaron{reg_sign}.

Parrot, I. M. [Institut Laue-Langevin (ILL); Urban, Volker S [ORNL; Gardner, K. H. [DuPont Experimental Station; Forsyth, V. T. [Institut Laue Langevin and Keele University

2005-04-01

311

Coherent x-ray zoom condenser lens for diffractive and scanning microscopy.  

PubMed

We propose a coherent x-ray zoom condenser lens composed of two-stage deformable Kirkpatrick-Baez mirrors. The lens delivers coherent x-rays with a controllable beam size, from one micrometer to a few tens of nanometers, at a fixed focal position. The lens is suitable for diffractive and scanning microscopy. We also propose non-scanning coherent diffraction microscopy for extended objects by using an apodized focused beam produced by the lens with a spatial filter. The proposed apodized-illumination method will be useful in highly efficient imaging with ultimate storage ring sources, and will also open the way to single-shot coherent diffraction microscopy of extended objects with x-ray free-electron lasers. PMID:23609637

Kimura, Takashi; Matsuyama, Satoshi; Yamauchi, Kazuto; Nishino, Yoshinori

2013-04-22

312

On the origin of sharp peaks in the X-ray diffraction patterns of xanthan powders.  

PubMed

A series of xanthans containing different levels of the charged group pyruvate has been examined. The X-ray diffraction patterns of the powders of these materials had different levels of a sharp pattern superimposed on an amorphous background. As the moisture content increased so the intensity of the sharp pattern increased up to a level between 20% and 40% moisture content where the sharp pattern disappeared. X-ray diffraction pattern identification software and an inorganic X-ray diffraction database showed the origin of the sharp peaks to be due to sodium sulphate polymorphs. The behaviour of the xanthans was thought to be due to the differences in charge on the molecule; however, the increase in the crystalline component observed with increased amounts of water was unexpected. The possibility of the drying of samples was considered but the interplay between ions, the charged polymer and the water present was considered necessary to more closely describe the results. PMID:23561220

Lad, M; Todd, T; Morris, G A; MacNaughtan, W; Sworn, G; Foster, T J

2013-02-11

313

Submicron X-Ray Diffraction and its Applications to Problems in Materials and Environmental Science  

SciTech Connect

The availability of high brilliance 3rd generation synchrotron sources together with progress in achromatic focusing optics allow to add submicron spatial resolution to the conventional century-old X-ray diffraction technique. The new capabilities include the possibility to map in-situ, grain orientations, crystalline phase distribution and full strain/stress tensors at a very local level, by combining white and monochromatic X-ray microbeam diffraction. This is particularly relevant for high technology industry where the understanding of material properties at a microstructural level becomes increasingly important. After describing the latest advances in the submicron X-ray diffraction techniques at the ALS, we will give some examples of its application in material science for the measurement of strain/stress in metallic thin films and interconnects. Its use in the field of environmental science will also be discussed.

Patel, J. R.

2002-08-16

314

Submicron X-ray diffraction and its applications to problems in materials and environmental science  

SciTech Connect

The availability of high brilliance 3rd generation synchrotron sources together with progress in achromatic focusing optics allow to add submicron spatial resolution to the conventional century-old X-ray diffraction technique. The new capabilities include the possibility to map in-situ, grain orientations, crystalline phase distribution and full strain/stress tensors at a very local level, by combining white and monochromatic X-ray microbeam diffraction. This is particularly relevant for high technology industry where the understanding of material properties at a microstructural level becomes increasingly important. After describing the latest advances in the submicron X-ray diffraction techniques at the ALS, we will give some examples of its application in material science for the measurement of strain/stress in metallic thin films and interconnects. Its use in the field of environmental science will also be discussed.

Tamura, N.; Celestre, R.S.; MacDowell, A.A.; Padmore, H.A.; Spolenak, R.; Valek, B.C.; Meier Chang, N.; Manceau, A.; Patel, J.R.

2002-03-26

315

Hard X-ray resonance in sapphire crystal cavities using back diffraction  

NASA Astrophysics Data System (ADS)

The Fabry-Perot type resonators using back diffraction from sapphire crystals for hard X-ray was investigated. On the basis of its less absorption and hexagonal structure, the resonator in sapphire crystals underwent a pure 2-beam diffraction which could enhance the resonance interference and improve finesse compared with the one in silicon crystals. The resonators were manufactured from sapphire crystals using microelectronic lithography process with thickness of a few tens ?m. With synchrotron radiation of energy resolution ?E=0.82 meV at 14.315 keV, X-ray back diffraction from two monolithic sapphire crystal plates shows resonance fringes clearly resulting from coherent interaction inside the energy gap of the (0 0 30) reflection. These experimental results of sapphire cavities imply the potential application for X-ray optics.

Wu, Y.-H.; Tsai, Y.-W.; Chang, Y.-Y.; Chu, C.-H.; Mikolas, David G.; Fu, C.-C.; Chang, S.-L.

2012-02-01

316

Pump-probe X-ray Diffraction Technique for Irreversible Phase Change Materials  

NASA Astrophysics Data System (ADS)

We have developed a pump-probe X-ray diffraction measurement system for a sample with irreversible reaction at BL40XU in the SPring-8. The system mainly consists of a time-resolved measurement system, a sample disk rotation system, and an X-ray microbeam system. The time-resolved measurement system gives time resolution of 50 ps in laser-pump and X-ray probe method. A sample disk rotation system for repetitive measurements was made to give a virgin sample for every measurement. The number of repetitions for one sample disk was increased by using the X-ray microbeam technique. To keep the overlap of the X-ray microbeam and the laser beam on the sample surface during the disk rotation, the sample disk rotation system was constructed by a low-eccentric spindle motor. By using this system, the pump-probe X-ray diffraction measurement was demonstrated for a crystallization process of a DVD material.

Fukuyama, Yoshimitsu; Yasuda, Nobuhiro; Kimura, Shigeru; Tanaka, Yoshihito; Osawa, Hitoshi; Kim, Jungeun; Murayama, Haruno; Moritomo, Yutaka; Toriumi, Koshiro; Tanaka, Hitoshi; Takata, Masaki

2010-06-01

317

Pump-probe X-ray Diffraction Technique for Irreversible Phase Change Materials  

SciTech Connect

We have developed a pump-probe X-ray diffraction measurement system for a sample with irreversible reaction at BL40XU in the SPring-8. The system mainly consists of a time-resolved measurement system, a sample disk rotation system, and an X-ray microbeam system. The time-resolved measurement system gives time resolution of 50 ps in laser-pump and X-ray probe method. A sample disk rotation system for repetitive measurements was made to give a virgin sample for every measurement. The number of repetitions for one sample disk was increased by using the X-ray microbeam technique. To keep the overlap of the X-ray microbeam and the laser beam on the sample surface during the disk rotation, the sample disk rotation system was constructed by a low-eccentric spindle motor. By using this system, the pump-probe X-ray diffraction measurement was demonstrated for a crystallization process of a DVD material.

Fukuyama, Yoshimitsu; Yasuda, Nobuhiro; Kimura, Shigeru; Osawa, Hitoshi; Kim, Jungeun [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Japan Science and Technology Agency, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); Tanaka, Yoshihito; Takata, Masaki [Japan Science and Technology Agency, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Murayama, Haruno [Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551 (Japan); Moritomo, Yutaka [Japan Science and Technology Agency, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8571 (Japan); Toriumi, Koshiro [Japan Science and Technology Agency, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); Tanaka, Hitoshi [RIKEN XFEL Joint Project/SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2010-06-23

318

Studies of Materials at the Nanometer Scale Using Coherent X-Ray Diffraction Imaging  

NASA Astrophysics Data System (ADS)

For many years, x-ray microscopy has been attractive for materials studies with its ability to image thick samples and provide nanometer-scale resolution. However, the ability to manufacture high-resolution x-ray optics has been a hurdle to achieving the full potential of diffraction limited x-ray imaging. Recently, the advent of bright and coherent x-ray sources at synchrotrons and x-ray free electron lasers has enabled a lensless imaging technique called coherent diffractive imaging (CDI). Since it was first demonstrated in 1999, CDI has been rapidly developing into a materials imaging technique with resolutions approaching a few nanometers. This review provides an overview of the development of CDI and several applications to nanometer-scale imaging in two and three dimensions of biological and condensed mater materials. Also, we review the development of tabletop, coherent, soft x-ray sources that provide a complimentary and potentially more accessible source for nanometer-scale coherent imaging of materials.

Sandberg, Richard L.; Huang, Zhifeng; Xu, Rui; Rodriguez, Jose A.; Miao, Jianwei

2013-09-01

319

X-ray powder diffraction characterization of pyrope  

Microsoft Academic Search

I332\\/I422, the intensity ratio of powder diffraction, is highly sensitive to variations in garnet composition and can be taken as an\\u000a identification criterion for pyrope: I332\\/I422 ~ 1 for pyrope while it is much smaller than unit for other members of the garnet group.

Wang Guanxin; Gong Guohong

1990-01-01

320

High-resolution inverted x-ray photoelectron diffraction studies of Si(100)  

Microsoft Academic Search

An inversion of the x-ray photoelectron diffraction (XPD) experiment has been performed in which incident electrons are diffracted to reach different sites within a crystal with differing relative probabilities reflecting those for escape of photoelectrons from the same sites in the corresponding XPD experiment. The diffracted-electron flux arriving at each site was monitored by using a Si(Li) detector to measure

Stephen Evans

1997-01-01

321

Diffractive-refractive optics: (+,-,-,+) X-ray crystal monochromator with harmonics separation.  

PubMed

A new kind of two channel-cut crystals X-ray monochromator in dispersive (+,-,-,+) position which spatially separates harmonics is proposed. The diffracting surfaces are oriented so that the diffraction is inclined. Owing to refraction the diffracted beam is sagittally deviated. The deviation depends on wavelength and is much higher for the first harmonics than for higher harmonics. This leads to spatial harmonics separation. The idea is supported by ray-tracing simulation. PMID:21335920

Hrdý, Jaromír; Mikulík, Petr; Oberta, Peter

2011-01-08

322

Coherent x-ray diffraction imaging of paint pigment particles by scanning a phase plate modulator  

NASA Astrophysics Data System (ADS)

We have implemented a coherent x-ray diffraction imaging technique that scans a phase plate to modulate wave-fronts of the x-ray beam transmitted by samples. The method was applied to measure a decorative alkyd paint containing iron oxide red pigment particles. By employing an iterative algorithm for wave-front modulation phase retrieval, we obtained an image of the paint sample that shows the distribution of the pigment particles and is consistent with the result obtained from a transmission x-ray microscope. The technique has been experimentally proven to be a feasible coherent x-ray imaging method with about 120 nm spatial resolution and was shown to work well with industrially relevant specimens.

Chen, Bo; Zhang, Fucai; Berenguer, Felisa; Bean, Richard J.; Kewish, Cameron M.; Vila-Comamala, Joan; Chu, Yong S.; Rodenburg, John M.; Robinson, Ian K.

2011-10-01

323

Coherent x-ray diffraction imaging of paint pigmentparticles by scanning a phase plate modulator  

SciTech Connect

We have implemented a coherent x-ray diffraction imaging technique that scans a phase plate to modulate wave-fronts of the x-ray beam transmitted by samples. The method was applied to measure a decorative alkyd paint containing iron oxide red pigment particles. By employing an iterative algorithm for wave-front modulation phase retrieval, we obtained an image of the paint sample that shows the distribution of the pigment particles and is consistent with the result obtained from a transmission x-ray microscope. The technique has been experimentally proven to be a feasible coherent x-ray imaging method with about 120 nm spatial resolution and was shown to work well with industrially relevant specimens.

Chu Y. S.; Chen B.; Zhang F.; Berenguer F.; Bean R.; Kewish C.; Vila-Comamala J.; Rodenburg J.; Robinson I.

2011-10-19

324

The X-ray Diffraction and Scattering Beamline and Results of the Performance Tests at NSRL  

SciTech Connect

Extending the spectral range to hard X-ray, a superconducting wiggler was constructed and installed at the 0.8 Gev storage ring of National Synchrotron Radiation Laboratory to produce a radiation with the critical energy of 2.55 keV. The wiggler radiation fan of horizontal 35 mrad has been split into three branches to be equipped with three beamlines for studies on extended X-ray absorption fine structure (XAFS), X-ray diffraction and scattering (XRDS) and X-ray deep lithography (LIGA), respectively. This paper reports the design, the results of performance tests of the XRDS beamline and the preliminary data collection on a protein crystal of acutohaemolysin at the experiment station.

Xu Chaoyin; Pan Guoqiang; Fan Rong; Huang Zhigang; Dong Xiaohao; Gao Fei; Feng Liangjie [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China); Lou Xiaohua [Department of Molecular and Cell Biology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230029 (China)

2004-05-12

325

Simulating Picosecond X-ray Diffraction from shocked crystals by Post-processing Molecular Dynamics Calculations  

SciTech Connect

Calculations of the x-ray diffraction patterns from shocked crystals derived from the results of Non-Equilibrium-Molecular-Dynamics (NEMD) simulations are presented. The atomic coordinates predicted by the NEMD simulations combined with atomic form factors are used to generate a discrete distribution of electron density. A Fast-Fourier-Transform (FFT) of this distribution provides an image of the crystal in reciprocal space, which can be further processed to produce quantitative simulated data for direct comparison with experiments that employ picosecond x-ray diffraction from laser-irradiated crystalline targets.

Kimminau, G; Nagler, B; Higginbotham, A; Murphy, W; Park, N; Hawreliak, J; Kadau, K; Germann, T C; Bringa, E M; Kalantar, D; Lorenzana, H; Remington, B; Wark, J

2008-06-19

326

A framework for 3-D coherent diffraction imaging by focused beam x-ray Bragg ptychography.  

SciTech Connect

We present the framework for convergent beam Bragg ptychography, and, using simulations, we demonstrate that nanocrystals can be ptychographically reconstructed from highly convergent x-ray Bragg diffraction. The ptychographic iterative engine is extended to three dimensions and shown to successfully reconstruct a simulated nanocrystal using overlapping raster scans with a defocused curved beam, the diameter of which matches the crystal size. This object reconstruction strategy can serve as the basis for coherent diffraction imaging experiments at coherent scanning nanoprobe x-ray sources.

Hruszkewycz, S. O.; Holt, M. V.; Tripathi, A.; Maser, J.; Fuoss, P. H. (Center for Nanoscale Materials); ( MSD); (Univ. of California at San Diego)

2011-06-15

327

X-ray diffraction and nanoindentation studies of nanocrystalline graphite at high pressures  

NASA Astrophysics Data System (ADS)

We report energy dispersive x-ray diffraction studies on nanocrystalline hexagonal graphite samples (average grain size=12 nm) in a diamond-anvil cell to 65 GPa at room temperature. A structural phase transition to a hexagonal diamond phase beginning at 15 GPa is completed at 55 GPa, and is reversible on decompression. The x-ray diffraction studies were followed by nanoindentation hardness measurements on the pressure treated samples. The obtained hardness values are in the range of 1-2 GPa. Unlike fullerenes, the room-temperature compression of nanocrystalline graphite to 65 GPa did not produce a superhard carbon material.

Patterson, J. Reed; Kudryavtsev, Anatoliy; Vohra, Yogesh K.

2002-09-01

328

Elastic properties of supported polycrystalline thin films and multilayers: An X-ray diffraction study  

SciTech Connect

Numerous experimental and theoretical studies have shown that thin film elastic behavior may be different from the bulk one due to size effects related to grain boundaries, free surfaces and interfaces. In addition, thin films often present high compressive residual stresses which may be responsible of thin film buckling. These two features will be discussed in this communication through recent x-ray diffraction experiments: in situ tensile testing for elastic constant analysis and scanning x-ray micro diffraction for stress relaxation measurements associated with film buckling.

Goudeau, P.; Villain, P.; Tamura, N.; Renault, P.-O.; Badawi, K.F.; Padmore, H.A.

2003-08-13

329

Toward the diffraction limit with transmissive x-ray lenses in astronomy.  

PubMed

We develop an analytical approach to refractive, blazed diffractive, and achromatic x-ray lenses of scalable dimensions for energies from 1 to 20 keV. Based on the parabolic wave equation, their wideband imaging properties are compared and optimized for a given spectral range. Low-Z lens materials for massive cores and rugged alternatives, such as polycarbonate or Si for flat Fresnel components, are investigated with respect to their suitability for diffraction-limited high-energy astronomy. Properly designed "hybrid" combinations can serve as an approach to x-ray telescopes with an enhanced efficiency throughout the whole considered band, nearly regardless of their inherent absorption. PMID:22781239

Braig, Christoph; Predehl, Peter

2012-07-10

330

Transmission diffraction-tomography system using a high-energy X-ray tube.  

PubMed

A high-energy bench-top energy dispersive X-ray diffraction (EDXRD) system for 3-dimensional mapping of the crystalline structure and phase transformations in steel is described, for which preliminary data and system development are presented here. The use of precision tungsten slit screens with up to 225 keV X-rays allows for diffraction through samples of 304 L austenitic stainless steel of thickness 3-10 mm, while sample positioning is carried out with a precision goniometer and translation stage system. PMID:19962905

Garrity, D J; Jenneson, P M; Crook, R; Vincent, S M

2009-10-01

331

X-ray diffraction studies on the thermal decomposition mechanism of nickel hydroxide.  

PubMed

Nickel hydroxide samples were prepared by using sodium hydroxide and ammonium hydroxide as precipitating agents. The powder X-ray diffraction pattern shows that the degrees of crystallinity in these samples are quite different. The thermal decomposition mechanism of these two nickel hydroxide samples has been determined using powder X-ray diffraction and thermogravimetric analysis. We observe that the transformation of nickel hydroxide to nickel oxide in the crystalline sample is via a two-phase mixture, whereas in a poorly ordered sample, it is through a single phase. This indicates that the decomposition mechanism mainly depends on the preparative conditions and the nature of the sample. PMID:19736947

Ramesh, Thimmasandra Narayan

2009-10-01

332

Nanoscale Imaging of Mineral Crystals inside Biological Composite Materials Using X-Ray Diffraction Microscopy  

NASA Astrophysics Data System (ADS)

We for the first time applied x-ray diffraction microscopy to the imaging of mineral crystals inside biological composite materials—intramuscular fish bone—at the nanometer scale resolution. We identified mineral crystals in collagen fibrils at different stages of mineralization. Based on the experimental results and biomineralization analyses, we suggested a dynamic model to account for the nucleation and growth of mineral crystals in the collagen matrix. The results obtained from this study not only further our understanding of the complex structure of bone, but also demonstrate that x-ray diffraction microscopy will become an important tool to study biological materials.

Jiang, Huaidong; Ramunno-Johnson, Damien; Song, Changyong; Amirbekian, Bagrat; Kohmura, Yoshiki; Nishino, Yoshinori; Takahashi, Yukio; Ishikawa, Tetsuya; Miao, Jianwei

2008-01-01

333

Mapping of residual strains of a ceramic-to-metal joint using X-ray diffraction  

SciTech Connect

In this study, the residual strains in the iron layer of a zirconia-iron joint, brazed with a metal alloy, were measured with X-ray diffraction as a function of distance from the joint. The residual strains were measured at various key locations indicated by a finite element model (FEM). The X-ray residual strain mapping results were compared to neutron diffraction mapping results. These data were combined to provide a complete residual strain profile of these samples and were compared with results of FEM.

Watkins, T.R.; Wang, X.L.; Spooner, S.; Hubbard, C.R.; Vance, S.J. [Oak Ridge National Lab., TN (United States); Rabin, B.H.; Williamson, R.L. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1994-03-01

334

X-ray and neutron diffraction determination of residual stresses in a pressed and welded component  

NASA Astrophysics Data System (ADS)

X-ray and neutron diffraction experiments have been carried out, in order to determine the residual stress (RS) field in a pressed and welded mock-up of an engine support for motor-bike technology. Such investigation is suggested by the need to know the stress state of the component after forming and welding. This allows to assess the quality of the first machining and further to theoretically simulate its performances under operation. Results are presented below, showing a good agreement between X-ray and neutron diffraction experiments.

Albertini, G.; Bruno, G.; Fiori, F.; Girardin, E.; Giuliani, A.; Quadrini, E.

2000-03-01

335

A structural determination using magnetic x-ray circular dichroism in spin-polarized photoelectron diffraction  

SciTech Connect

The first structural determination with spin-polarized, energy-dependent photoelectron diffraction using circularly-polarized x-rays is reported for Fe films on Cu(001). Circularly-polarized x-rays produce spin-polarized photoelectrons from the Fe 2p doublet, and intensity asymmetries in the 2p{sup 3/2} level are observed. . Fully spin-specific multiple scattering calculations reproduce the experimentally determined energy and angular dependences. A new analytical procedure which focuses upon intensity variations due to spin-dependent diffraction is introduced.

Waddill, G.D.; Tobin, J.G. [Lawrence Livermore National Lab., CA (United States); Guo, X.; Tong, S.Y. [Wisconsin Univ., Milwaukee, WI (United States)

1994-05-26

336

Development of X-ray photoelectron microscope with a compact X-ray source generated by line-focused laser irradiation  

Microsoft Academic Search

A laboratory-sized X-ray photoelectron microscope was constructed using a compact X-ray source produced by line-focused laser irradiation. The system is a scanning type photoelectron microscope where X-ray beam is micro-focused via Schwarzschild optics. A compact laser-plasma X-ray source has been developed with a YAG laser, a line-focus lens assembly, an Al tape-target driver and a debris prevention system. The 13.1nm

N. Yamaguchi; Z. Takahashi; Y. Nishimura; K. Watanabe; Y. Okamoto; A. Sakata; H. Azuma; T. Hara

2005-01-01

337

Soft X-Ray Microscopy at HZB: Zone Plate Development and Imaging Using the Third Order of Diffraction  

SciTech Connect

The Helmholtz-Zentrum Berlin (HZB) operates a transmission x-ray microscope (TXM) in the soft x-ray photon energy range with an energy resolution up to E/{Delta}E = 10{sup 4}. An approach to achieve ultrahigh spatial resolution with conventional, standard zone plate optics is to employ higher orders of diffraction of the zone plate objective. In this paper, we demonstrate that 11-nm lines and spaces of a multilayer test structure are clearly resolved by the x-ray microscope using the third order of diffraction of a zone plate objective with 20-nm outermost zone width. The disadvantage of high-order imaging is an about one order of magnitude lower diffraction efficiency of the used zone plates employed in the third order compared to the first order of diffraction. In addition, the measured background signal in the TXM images is no longer negligible. Therefore, we worked on the fabrication of zone plates with sub-20-nm outermost zone width to increase the spatial resolution in the first order of diffraction. A new high-resolution 100-keV e-beam lithography system from VISTEC, which was recently installed at the Helmholtz-Zentrum Berlin, makes these developments possible. Initial results on zone plates with an outermost zone width down to 15 nm exposed with the new e-beam system are presented. Furthermore, the contrast transfer function of the transmission x-ray microscope operating in partial coherence mode is measured by using the first and third diffraction order of the zone plate objective.

Rehbein, S.; Guttmann, P.; Werner, S.; Schneider, G. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Wilhelm-Conrad-Roentgen-Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin (Germany)

2011-09-09

338

Multiple-wave diffraction in high energy resolution back-reflecting x-ray optics.  

PubMed

We have studied the effects of multiple-wave diffraction in a novel optical scheme recently published by Shvyd'ko et al. utilizing Bragg diffraction of x rays in backscattering geometry from asymmetrically cut crystals for achieving energy resolutions beyond the intrinsic width of the Bragg reflection. By numerical simulations based on dynamic x-ray diffraction and by experimentation involving two-dimensional angular scans of the back-reflecting crystal, multiple-wave diffraction was found to contribute up to several tens percent loss of efficiency but can be avoided without degrading the energy resolution of the original scheme by careful choice of azimuthal orientation of the diffracting crystal surface and by tilting of the crystal perpendicular to the dispersion plane. PMID:22107300

Stetsko, Yuri P; Keister, J W; Coburn, D S; Kodituwakku, C N; Cunsolo, A; Cai, Y Q

2011-10-07

339

New software to model energy dispersive X-ray diffraction in polycrystalline materials  

NASA Astrophysics Data System (ADS)

Detection of illicit materials, such as explosives or drugs, within mixed samples is a major issue, both for general security and as part of forensic analyses. In this paper, we describe a new code simulating energy dispersive X-ray diffraction patterns in polycrystalline materials. This program, SinFullscat, models diffraction of any object in any diffractometer system taking all physical phenomena, including amorphous background, into account. Many system parameters can be tuned: geometry, collimators (slit and cylindrical), sample properties, X-ray source and detector energy resolution. Good agreement between simulations and experimental data was obtained. Simulations using explosive materials indicated that parameters such as the diffraction angle or the energy resolution of the detector have a significant impact on the diffraction signature of the material inspected. This software will be a convenient tool to test many diffractometer configurations, providing information on the one that best restores the spectral diffraction signature of the materials of interest.

Ghammraoui, B.; Tabary, J.; Pouget, S.; Paulus, C.; Moulin, V.; Verger, L.; Duvauchelle, Ph.

2012-02-01

340

Multiple-Wave Diffraction in High Energy Resolution Back-Reflecting X-Ray Optics  

SciTech Connect

We have studied the effects of multiple-wave diffraction in a novel optical scheme recently published by Shvyd'ko et al. utilizing Bragg diffraction of x rays in backscattering geometry from asymmetrically cut crystals for achieving energy resolutions beyond the intrinsic width of the Bragg reflection. By numerical simulations based on dynamic x-ray diffraction and by experimentation involving two-dimensional angular scans of the back-reflecting crystal, multiple-wave diffraction was found to contribute up to several tens percent loss of efficiency but can be avoided without degrading the energy resolution of the original scheme by careful choice of azimuthal orientation of the diffracting crystal surface and by tilting of the crystal perpendicular to the dispersion plane.

Stetsko, Yuri P.; Keister, J. W.; Coburn, D. S.; Kodituwakku, C. N.; Cunsolo, A.; Cai, Y. Q. [National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973 (United States)

2011-10-07

341

Novel algorithms in coherent diffraction imaging using x-ray free-electron lasers  

NASA Astrophysics Data System (ADS)

The emergence of X-ray Free-Electron Lasers has enabled coherent diffraction imaging of single nanoparticles by outrunning radiation damage with an intense ultrafast X-ray pulse. A 3D reconstruction from an ensemble of 2D diffraction patterns requires recovery of the orientations of individual diffraction patterns. This assumes that each diffraction pattern comes from a slice of a common diffraction volume. In the presence of particle heterogeneity, this assumption does not hold and the recovered structure is severely degraded. In this paper, I review couple of emerging algorithms useful for dealing with conformational changes in a heterogeneous sample. A simulated case study of a "particle in motion" is included to demonstrate the algorithms and also show that these novel algorithms work in the presence of missing Fourier regions caused by new detector geometries at XFEL facilities.

Yoon, Chunhong

2012-10-01

342

Protegrin interaction with lipid monolayers: Grazing incidence X-ray diffraction and X-ray reflectivity study  

PubMed Central

Interactions of the antimicrobial peptide protegrin-1 (PG-1) with phospholipid monolayers have been investigated by using grazing incidence X-ray diffraction (GIXD) and specular X-ray reflectivity (XR). The structure of a PG-1 film at the air-aqueous interface was also investigated by XR for the first time. Lipid A, dipalmitoyl-phosphatidylglycerol (DPPG) and dipalmitoyl-phosphatidylcholine (DPPC) monolayers were formed at the air-aqueous interface to mimic the surface of the bacterial cell wall and the outer leaflet of the erythrocyte cell membrane, respectively. Experiments were carried out under constant area conditions where the pressure changes upon insertion of peptide into the monolayer. GIXD data suggest that the greatest monolayer disruption produced by PG-1 is seen with the DPPG system at 20 mN/m since the Bragg peaks completely disappear after introduction of PG-1 to the system. PG-1 shows greater insertion into the lipid A system compared to the DPPC system when both films are held at the same initial surface pressure of 20 mN/m. The degree of insertion lessens at 30 mN/m with both DPPC and DPPG monolayer systems. XR data further reveal that PG-1 inserts primarily in the head group region of lipid monolayers. However, only the XR data of the anionic lipids suggest the existence of an additional adsorbed peptide layer below the head group of the monolayer. Overall the data show that the extent of peptide/lipid interaction and lipid monolayer disruption depends not only on the lipid composition of the monolayer, but the packing density of the lipids in the monolayer prior to the introduction of peptide to the subphase.

Neville, Frances; Ishitsuka, Yuji; Hodges, Chris S.; Konovalov, Oleg; Waring, Alan J.; Lehrer, Robert; Lee, Ka Yee C.; Gidalevitz, David

2009-01-01

343

Single-Shot Femtosecond X-ray Diffraction from Randomly Oriented Ellipsoidal Nanoparticles  

SciTech Connect

Coherent diffractive imaging of single particles using the single-shot 'diffract and destroy' approach with an x-ray free electron laser (FEL) was recently demonstrated. A high-resolution low-noise coherent diffraction pattern, representative of the object before it turns into a plasma and explodes, results from the interaction of the FEL with the particle. Iterative phase retrieval algorithms are used to reconstruct two-dimensional projection images of the object from the recorded intensities alone. Here we describe the first single-shot diffraction data set that mimics the data proposed for obtaining 3D structure from identical particles. Ellipsoidal iron oxide nanoparticles (250 nm x 50 nm) were aerosolized and injected through an aerodynamic lens stack into a soft x-ray FEL. Particle orientation was not controlled with this injection method. We observed that, at the instant the x-ray pulse interacts with the particle, a snapshot of the particle's orientation is encoded in the diffraction pattern. The results give credence to one of the technical concepts of imaging individual nanometer and subnanometer-sized objects such as single molecules or larger clusters of molecules using hard x-ray FELs and will be used to help develop robust algorithms for determining particle orientations and 3D structure.

Bogan, M.J.; /SLAC; Boutet, S.; /SLAC; Barty, A.; /LLNL, Livermore /DESY; Benner, W.H.; Frank, M.; /LLNL, Livermore; Lomb, L.; Shoeman, R.; /Heidelberg, Max Planck Inst. Med. Res. /CFEL, Hamburg; Starodub, D.; /SLAC; Seibert, M.M.; /Uppsala U.; Hau-Riege, S.P.; Woods, B.; /LLNL, Livermore; Decorwin-Martin, P.; /SLAC; Bajt, S.; /DESY; Schulz, J.; /DESY; Rohner, U.; /LLNL, Livermore /Unlisted, CH; Iwan, B.; Timneanu, N.; /Uppsala U.; Marchesini, S.; /LBL, Berkeley; Schlichting, I.; /Heidelberg, Max Planck Inst. Med. Res. /CFEL, Hamburg; Hajdu, J.; /Uppsala U.; Chapman, H.N.; /DESY /Hamburg U., Inst. Theor. Phys. II

2012-04-18

344

Experimental methods for optimal tuning of bendable mirrors for diffraction-limited soft x-ray focusing  

NASA Astrophysics Data System (ADS)

We report on hands-on experimental methods developed at the Advanced Light Source (ALS) for optimal tuning of mechanically bendable x-ray mirrors for diffraction-limited soft x-ray nano-focusing. For ex situ tuning of the benders for optimal beam-line performance, we use a revised version of the method of characteristic functions recently developed at the ALS optical metrology laboratory. At-wavelength optimal tuning of bendable optics consists of a series of wavefront-sensing tests with increasing accuracy and sensitivity, including modified scanning-slit Hartmann tests. The methods have been experimentally validated at ALS test beamline 5.3.1 and the micro-diffraction beamline 12.3.2 in applications to optimally set bendable Kirkpatrick-Baez mirrors designed for sub-micron focusing.

Yashchuk, V. V.; Merthe, D. J.; Goldberg, K. A.; Artemiev, N. A.; Celestre, R.; Domning, E. E.; Kunz, M.; McKinney, W. R.; Morrison, G. Y.; Smith, B. V.; Tamura, N.

2013-03-01

345

Determination of multiwavelength anomalous diffraction coefficients at high x-ray intensity  

NASA Astrophysics Data System (ADS)

The high-intensity version of multiwavelength anomalous diffraction (MAD) has a potential for solving the phase problem in femtosecond crystallography with x-ray free-electron lasers (XFELs). For MAD phasing, it is required to calculate or measure the MAD coefficients involved in the key equation, which depend on XFEL pulse parameters. In this work, we revisit the generalized Karle-Hendrickson equation to clarify the importance of configurational fluctuations of heavy atoms induced by intense x-ray pulses, and investigate the high-intensity cases of transmission and fluorescence measurements of samples containing heavy atoms. Based on transmission/fluorescence and diffraction experiments with crystalline samples of known structures, we propose an experimental procedure to determine all MAD coefficients at high x-ray intensity, which can be used in ab initio phasing for unknown structures.

Son, Sang-Kil; Chapman, Henry N.; Santra, Robin

2013-08-01

346

Coherent X-Ray Diffraction Imaging of Morphology and Strain in Nanomaterials  

NASA Astrophysics Data System (ADS)

The last decade has seen a remarkable surge in x-ray characterization methods (Willmott, An Introduction to Synchrotron Radiation, John Wiley & Sons, Inc., New York, 2011). Imaging with x-rays has evolved from simple radiography, to image internal structure and diagnose injury, to a full-fledged tool for nanoscale characterization (Holt et al., Annu Rev Mater Res 43:1, 2013). Central to this development has been the advent of high-brilliance synchrotron and free electron laser sources of x-rays. The high degree of spacial coherence of the resulting beams has enabled novel imaging methods. Of these, coherent diffraction imaging has proven highly successful at imaging the structure in nano materials (Miao et al., Nature 400:342, 1999). In addition, this imaging method can be combined with Bragg diffraction to image strain with high sensitivity (Pfeifer et al., Nature 442:63, 2006; Robinson and Harder, Nat Mater 8:291, 2009).

Harder, Ross; Robinson, Ian K.

2013-09-01

347

Axial electron density of human scleral collagen. Location of proteoglycans by x-ray diffraction.  

PubMed Central

The low angle meridional x-ray diffraction pattern from fresh human sclera was analyzed to ascertain if collagen-bound proteoglycans affect the axially-projected electron density distribution to the same extent as appears to occur in the cornea. The results showed that, unlike cornea, the electron density of the sclera is similar to that seen in rat tail tendon collagen. The proteoglycans were specifically stained using either Cuprolinic blue or Cupromeronic blue, both under critical electrolyte conditions. The tissue was then examined by electron microscopy and by low angle x-ray diffraction. The electron-optical observations suggested that proteoglycans associate with collagen near the d/e staining bands in the gap zone. A difference Fourier analysis from the x-ray results confirmed that these observations were not e.m. preparative artefacts and allowed a quantitative estimate to be made of the axial extent of the proteglycans in the wet tissue. Images FIGURE 1 FIGURE 3

Quantock, A J; Meek, K M

1988-01-01

348

X-ray diffraction of indirect flight muscle from Drosohila in vivo  

SciTech Connect

The indirect flight muscle (IFM) of the fruit fly, Drosophila, represents a powerful model system for integrated structure and function studies because of the ease of genetically manipulating this organism. Recent advances in synchrotron technology have allowed collection of high quality two dimensional x-ray fiber diffraction patterns from the IFM of living fruit flies both at rest and during tethered flight. Based on many decades of x-ray and electron microscopic studies of vertebrate muscle and IFM from the waterbug, Lethocerus, there now exists a framework for interpreting changes in the x-ray diffraction patterns in terms of structural changes at the myofilament level. These developments allow testing of hypotheses concerning muscle function in a truly in vivo system.

Irving, T. (IIT)

2007-02-09

349

Data management and visualization of x-ray diffraction spectra from thin film ternary composition spreads  

SciTech Connect

We discuss techniques for managing and visualizing x-ray diffraction spectrum data for thin film composition spreads which map large fractions of ternary compositional phase diagrams. An in-house x-ray microdiffractometer is used to obtain spectra from over 500 different compositions on an individual spread. The MATLAB software is used to quickly organize the data and create various plots from which one can quickly grasp different information regarding structural and phase changes across the composition spreads. Such exercises are valuable in rapidly assessing the 'overall' picture of the structural evolution across phase diagrams before focusing in on specific composition regions for detailed structural analysis. We have also shown that simple linear correlation analysis of the x-ray diffraction peak information (position, intensity and full width at half maximum) and physical properties such as magnetization can be used to obtain insight about the physical properties.

Takeuchi, I.; Long, C.J.; Famodu, O.O.; Murakami, M.; Hattrick-Simpers, J.; Rubloff, G.W.; Stukowski, M.; Rajan, K. [Department of Materials Science and Engineering and Center for Superconducting Research, University of Maryland, College Park, Maryland 20742 (United States); Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2005-06-15

350

Synchrotron x-ray diffraction measurements of strain in metallic nanoparticles with oxide shells.  

SciTech Connect

We describe synchrotron x-ray diffraction measurements of strain in Cu and Pd metal nanoparticles (1.7-40 nm diameter) both with an air-formed oxide shell and after reduction of the oxide by treatment in a hydrogen-containing atmosphere. Oxide removal is evident from x-ray diffraction (for Cu) and x-ray absorption spectroscopy (for Pd). A simple model that uses bulk elastic properties is applied to each system. In the Pd case the model predictions agree well with the experiment. For Cu the observed strains are much smaller than predicted. This discrepancy is attributed to (a) the presence of multiple grains within the Cu particles and (b) the incoherency of the oxide with the metal core.

Ingham, B.; Hendy, S. C.; Fong, D. D.; Fuoss, P. H.; Eastman, J. A.; Lassesson, A.; Tee, K .C.; Convers, P. Y.; Brown, S. A.; Ryan, M. P.; Toney, M. F.; Materials Science Division; Industrial Research Ltd.; The MacDiarmid Inst. for Advanced Materials and Nanotechnology; Univ. of Canterbury; Imperial Coll. London; Stanford Synchrotron Radiation Lightsource

2010-02-04

351

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

NASA Astrophysics Data System (ADS)

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

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

2002-01-01

352

Use of X-ray diffraction in a study of ammonia leaching of multimetal sulfides  

NASA Astrophysics Data System (ADS)

X-ray diffraction has been used to study the changes in mineralogy that occur during ammonia leaching of sulfide minerals and complex bulk sulfide concentrates. Leaching results in high extraction rates (>90 pct) of copper from chalcopyrite, zinc from sphalerite, and lead from galena. However, under experimental leaching conditions (temperature, 115 °C to 135 °C; par-tial pressure of oxygen, 1.5 kg/cm2; pH ˜ 10.0), the pyrite grains are practically inert. Ap-parently, the amount of pyrite in leach residue is constant in absolute terms. However, its relative percentage changes because the amount of copper and zinc minerals is reduced in the leach residue during progressive leaching. The products formed during the leaching reaction, such as goethite and lead sulfate, tend to increase the weight of the leach residue, and thus the relative weight of pyrite remains nearly unchanged. The ratios of selected line pair intensities of pyrite lines and characteristic (selected) lines of chalcopyrite, sphalerite, and galena are used to establish the oxidative ammonia leaching kinetics of Cu-Zn-Pb bulk concentrates. That is, the variation in the line pair intensity ratios, with time, correlates with the changes in the el-emental concentrations in the leach liquor.

Rao, K. Sarveswara; Das, R. P.; Mukunda, P. G.; Ray, H. S.

1993-12-01

353

Phase tomography from x-ray coherent diffractive imaging projections.  

PubMed

Coherent diffractive imaging provides accurate phase projections that can be tomographically combined to yield detailed quantitative 3D reconstructions with a resolution that is not limited by imaging optics. We present robust algorithms for post-processing and alignment of these tomographic phase projections. A simple method to remove undesired constant and linear phase terms on the reconstructions is given. Also, we provide an algorithm for automatic alignment of projections that has good performance even for samples with no fiducial markers. Currently applied to phase projections, this alignment algorithm has proven to be robust and should also be useful for lens-based tomography techniques that pursue nanoscale 3D imaging. Lastly, we provide a method for tomographic reconstruction that works on phase projections that are known modulo 2?, such that the phase unwrapping step is avoided. We demonstrate the performance of these algorithms by 3D imaging of bacteria population in legume root-nodule cells. PMID:22108985

Guizar-Sicairos, Manuel; Diaz, Ana; Holler, Mirko; Lucas, Miriam S; Menzel, Andreas; Wepf, Roger A; Bunk, Oliver

2011-10-24

354

Applications of Synchrotron-Based X-Ray Diffraction and X-Ray Absorption Spectroscopy to the Understanding of Poorly Crystalline and Metal-Substituted Iron Oxides  

Microsoft Academic Search

The octahedral site in iron oxides has been shown to undergo changes in its occupation when iron oxides form in the presence of single and multiple foreign metals in controlled laboratory settings as well as the natural environment. X-ray absorption spectroscopy coupled with the increased precision of synchrotron-based X-ray diffraction (SXRD) have shed new light on important basic mechanisms controlling

Balwant Singh; Markus Gräfe; Navdeep Kaur; Andrea Liese

2010-01-01

355

Two-dimensional measurement of focused hard X-ray beam profile using coherent X-ray diffraction of isolated nanoparticle  

Microsoft Academic Search

A method for evaluating the two-dimensional photon density distribution in focused hard X-ray beams is proposed and demonstrated in a synchrotron experiment at SPring-8. A synchrotron X-ray beam of 11.8keV is focused to a ?1?m spot by Kirkpatrick–Baez mirrors. The two-dimensional intensity distribution of the focused beam is derived by monitoring the forward diffracted intensity from an isolated silver nanocube

Yukio Takahashi; Hideto Kubo; Ryosuke Tsutsumi; Shigeyuki Sakaki; Nobuyuki Zettsu; Yoshinori Nishino; Tetsuya Ishikawa; Kazuto Yamauchi

2010-01-01

356

Metastable phase diagram of Bi probed by single-energy x-ray absorption detection and angular dispersive x-ray diffraction  

Microsoft Academic Search

In this paper we report the results of a detailed experimental study of samples composed of micrometric Bi droplets providing an insight into the metastable phase diagram of Bi. To this purpose we have used the single-energy x-ray absorption detection technique in combination with angular dispersive x-ray diffraction available at the BM29 beamline of the European Synchrotron Radiation Facility. This

E. Principi; M. Minicucci; A. Di Cicco; A. Trapananti; S. De Panfilis; R. Poloni

2006-01-01

357

Si\\/1ML-Ge\\/Si(001) Interface Structure Characterized by Surface X-Ray Diffraction and X-Ray Standing-Wave Method  

Microsoft Academic Search

The structure of a delta-doped crystal, Si(800Å)\\/Ge(1ML)\\/Si(001), grown by molecular beam epitaxy has been studied by surface X-ray diffraction and X-ray standing-wave method. The positions of the Ge layer and the Si capping layer are determined with respect to the Si substrate. In the analysis, the roughnesses of the interface and the surface are considered. The distance between the bottommost

Masamitu Takahasi; Shinichiro Nakatani; Toshio Takahashi; Xiaowei Zhang; Masami Ando; Susumu Fukatsu; Yasuhiro Shiraki

1995-01-01

358

X-ray diffraction and extended X-ray absorption fine-structure study of RMn 2 hydrides (R = Y, Gd or Dy)  

Microsoft Academic Search

Structural properties of RMn2 hydrides (R = Y, Gd or Dy) have been studied by means of powder X-ray diffraction (XRD) at 300 K and extended X-ray absorption fine structure (EXAFS) at 300 K and low temperatures. It was found that at 300 K the lattice parameters increase continuously upon hydrogen absorption (except for DyMn2Hx with x < 1) and

J. Przewo?nik; V. Paul-Boncour; M. Latroche; A. Percheron-Guégan

1996-01-01

359

High-resolution X-ray diffraction and X-ray reflectivity studies of short-period CdTe\\/MnTe-superlattices  

Microsoft Academic Search

CdTe\\/MnTe superlattices have recently been focused on because of their magnetic properties, in particular, the magnetic coupling of the MnTe layers across the CdTe interlayers. The aim of the present paper is the determination of the structural parameters of short-period CdTe\\/MnTe superlattice samples by means of X-ray diffraction and X-ray reflectivity studies, as these parameters are essential for the interpretation

J. Stangl; A. A. Darhuber; V. Holý; M. de Naurois; S. Ferreira; W. Faschinger; G. Bauer

1998-01-01

360

X-ray Diffraction Study of Nano SnO2.  

National Technical Information Service (NTIS)

Semiconductor SnO2 with nanosize microstructure was prepared by sol-gel method. The X-ray diffraction spectra of powder and compact cake are all with abnormal broadened symmetric peaks. Porous nanometer structure is confirmed by Transmission Electron Micr...

D. Z. Wang Y. Huang Y. Luo

1994-01-01

361

The energy dispersive X-ray diffraction method: annotated bibliography 1968–78  

Microsoft Academic Search

The present summary is a brief survey of the energy dispersive X-ray diffraction (EDXRD) method and an appraisal of the current position. A comprehensive chronological list of annotated references on EDXRD is given, covering the period 1968 to 1978. An index of authors is appended.

E. Laine; I. Lähteenmäki

1980-01-01

362

The energy dispersive X-ray diffraction method: annotated bibliography 1968–78  

Microsoft Academic Search

The present summary is a brief survey of the energy dispersive X-ray diffraction (EDXRD) method and an appraisal of the current\\u000a position. A comprehensive chronological list of annotated references on EDXRD is given, covering the period 1968 to 1978.\\u000a An index of authors is appended.

E. Laine; I. Lähteenmäki

1980-01-01

363

X-ray photoelectron diffraction of Ni(110)-2 × 1CO p2mg layer  

Microsoft Academic Search

The ordered adsorbed CO layer of (2 × 1) p2mg symmetry on a Ni(110) surface was studied by X-ray photoelectron diffraction over a polar angle range Theta = ± 85° and for four different azimuthal orientations. Forward scattering enhancement peaks in the C 1s photoelectron intensity were detected at various angles, being due to intramolecular as well as intermolecular scattering.

O. Knauff; U. Grosche; H. P. Bonzel; V. Fritzsche

1992-01-01

364

X-ray photoelectron diffraction of (100)-oriented chemical vapor deposited diamond films on silicon (100)  

Microsoft Academic Search

(100)-oriented diamond films have been grown on silicon (100) in a microwave plasma assisted chemical vapor deposition (CVD) tubular system. X-ray photoelectron diffraction (XPD) has been used to study such oriented polycrystalline films. Comparing the diffractograms of a natural diamond (100) surface and of polycrystalline (100)-oriented CVD diamond films quite similar features are observed. XPD measurements after 8 min of

E. Schaller; O. M. Küttel; P. Aebi; L. Schlapbach

1995-01-01

365

Structural Order-Disorder Transformations Monitored by X-Ray Diffraction and Photoluminescence  

ERIC Educational Resources Information Center

|A study was conducted to examine the structural order-disorder transformation promoted by controlled heat treatment using X-ray diffraction technique (XRD) and photoluminescence (PL) techniques as tools to monitor the degree of structural order. The experiment was observed to be versatile and easily achieved with low cost which allowed producing…

Lima, R. C.; Paris, E. C.; Leite, E. R.; Espinosa, J. W. M.; Souza, A. G.; Longo, E.

2007-01-01

366

X-ray diffraction and molecular modeling studies of cellulose and its interaction with xyloglucan  

Microsoft Academic Search

Polysaccharides have widespread commercial uses and play important roles in biological systems. The structures and interactions of two polysaccharides, cellulose and xyloglucan, are investigated using molecular modeling and x-ray fiber diffraction analysis. Cellulose is a high molecular weight polymer of glucose and is an essential component of plant structure and function. Xyloglucans have a cellulosic backbone that is heavily substituted

Victoria Lynne Finkenstadt

1997-01-01

367

X-ray diffraction phase analysis of the crystalline phase of polytetrafluoroethylene  

SciTech Connect

Samples of ultradispersed polytetrafluoroethylene, which were prepared with the use of different technological approaches, were studied by X-ray diffraction. The samples were found to belong to the monoclinic system. For some samples, basal reflections, which can be related to paraffins, were found for the first time. This indicates that polymer chains can form yet another type of monoclinic structure.

Lebedev, Yu. A., E-mail: y_lebedev@mail.ru; Korolev, Yu. M.; Rebrov, A. V. [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation); Ignat'eva, L. N. [Russian Academy of Sciences, Institute of Chemistry, Far East Division (Russian Federation); Antipov, E. M. [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation)

2010-07-15

368

Phases of Pb/Ge(111): A Surface X-Ray Diffraction Study.  

National Technical Information Service (NTIS)

This report describes the results of several surface X-ray diffraction measurements of a chemisorbed overlayer of Pb on the Ge(111) surface. Three phases of Pb/Ge(111) exist in the monolayer regime: the alpha - and beta -phases with a sqrt 3x sqrt 3R30(su...

F. Grey

1988-01-01

369

Deep X-Ray Lithography in the Fabrication Process of a 3D Diffractive Optical Element  

Microsoft Academic Search

We present first results of the fabrication process of a diffractive optical element (DOE) using deep X-ray lithography. The DOE forms the core of our proposed fast parallel-processing infrared Fourier transform interferometer (FPP FTIR) that works without moving parts and may allow instantaneous spectral analysis only limited by detector bandwidth. Design and specifications of the DOE are discussed. A fabrication

S. P. Heussler; H. O. Moser; C. G. Quan; C. J. Tay; K. D. Moeller; M. Bahou; L. K. Jian

2007-01-01

370

X-Ray Powder Diffraction as a Tool for the Identification of Impact Deformed Rocks  

Microsoft Academic Search

Previous X-ray powder diffraction (XRD) studies indicated shock deformed minerals have broader XRD peaks when compared to those of unshocked samples. Entire XRD patterns, single peak profiles and Rietveld refined parameters of carbonate samples from the Sierra Madera impact crater, west Texas and the Mission Canyon Formation of southwest Montana and western Wyoming were used to evaluate the use of

S. Huson; M. Pope; F. Foit; A. Watkinson

2007-01-01

371

Influence of X-Ray Diffraction Sample Preparation on Quantitative Mineralogy: Implications for Chromate Waste Treatment  

Microsoft Academic Search

Powders of chromite ore processing residue (COPR) were mineral- ogically evaluated using quantitative X-ray powder diffraction (XRPD) to illustrate the impacts of sample preparation procedures. Chromite ore processing residue is strongly alkaline, reactive, contains minerals of varying hardness and absorption coefficients, and exhibits signifi- cant amorphicity. This posesa challenge to produce powdersfor XRPD analysis that are sufficiently fine and of

Dimitris Dermatas; Maria Chrysochoou; Sarra Pardali; Dennis G. Grubb

372

X-ray diffraction study on crystal deformation of TbCo2  

NASA Astrophysics Data System (ADS)

X-ray diffraction work on single crystal of TbCo2 was carried out by a four circle automated counter diffractometer. Its cubic lattice distorts slightly into a rhombohedral lattice at temperature below Tc. The positional parameter of Tb atoms below Tc was determined for the first time. The crystal deformation was found to accompany no internal optical mode.

Yoshimoto, N.; Sakurai, J.; Komura, Y.

1983-02-01

373

High numerical aperture tabletop soft x-ray diffraction microscopy with 70-nm resolution.  

PubMed

Light microscopy has greatly advanced our understanding of nature. The achievable resolution, however, is limited by optical wavelengths to approximately 200 nm. By using imaging and labeling technologies, resolutions beyond the diffraction limit can be achieved for specialized specimens with techniques such as near-field scanning optical microscopy, stimulated emission depletion microscopy, and photoactivated localization microscopy. Here, we report a versatile soft x-ray diffraction microscope with 70- to 90-nm resolution by using two different tabletop coherent soft x-ray sources-a soft x-ray laser and a high-harmonic source. We also use field curvature correction that allows high numerical aperture imaging and near-diffraction-limited resolution of 1.5lambda. A tabletop soft x-ray diffraction microscope should find broad applications in biology, nanoscience, and materials science because of its simple optical design, high resolution, large depth of field, 3D imaging capability, scalability to shorter wavelengths, and ultrafast temporal resolution. PMID:18162534

Sandberg, Richard L; Song, Changyong; Wachulak, Przemyslaw W; Raymondson, Daisy A; Paul, Ariel; Amirbekian, Bagrat; Lee, Edwin; Sakdinawat, Anne E; La-O-Vorakiat, Chan; Marconi, Mario C; Menoni, Carmen S; Murnane, Margaret M; Rocca, Jorge J; Kapteyn, Henry C; Miao, Jianwei

2007-12-27

374

Synchrotron X-ray diffraction characterization of healthy and fluorotic human dental enamel  

NASA Astrophysics Data System (ADS)

With the introduction of fluoride as the main anticaries agent used in preventive dentistry, and perhaps an increase in fluoride in our food chain, dental fluorosis has become an increasing world-wide problem. Visible signs of fluorosis begin to become obvious on the enamel surface as opacities, implying some porosity in the tissue. The mechanisms that conduct the formation of fluorotic enamel are unknown, but should involve modifications in the basic physical-chemistry reactions of demineralization and remineralisation of the enamel of the teeth, which is the same reaction of formation of the enamel's hydroxyapatite (HAp) in the maturation phase. The increase of the amount of fluoride inside of the apatite will result in gradual increase of the lattice parameters. The aim of this work is to characterize the healthy and fluorotic enamel in human tooth using Synchrotron X-ray diffraction. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the Brazilian Synchrotron Light Laboratory—LNLS, Campinas, Brazil. X-ray diffraction experiments were performed both in powder samples and polished surfaces. The powder samples were analyzed to obtain the characterization of a typical healthy enamel pattern. The polished surfaces were analyzed in specific areas that have been identified as fluorotic ones. X-ray diffraction data were obtained for all samples and these data were compared with the control samples and also with the literature data.

Colaço, M. V.; Barroso, R. C.; Porto, I. M.; Gerlach, R. F.; Costa, F. N.; Braz, D.; Droppa, R.; de Sousa, F. B.

2012-10-01

375

Combined in situ X-ray diffraction and Raman spectroscopy on majoritic garnet inclusions in diamonds  

Microsoft Academic Search

Mineral inclusions in Sao Luiz diamonds have been characterized using angle dispersive X-ray diffraction and Raman spectroscopy. We identified two different garnet phases coexisting with an omphacitic pyroxene. They represent disintegration products of a former homogeneous majorite-rich garnet phase. The two garnets have significantly different cell parameters but are tightly intergrown with their unit cells parallel to each other. The

Martin Kunz; Philippe Gillet; Guillaume Fiquet; Violaine Sautter; Heinz Graafsma; Pamela Conrad; Jeff Harris

2002-01-01

376

High spatial resolution X-ray and gamma ray imaging system using diffraction crystals  

DOEpatents

A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.

Smither, Robert K. (Hinsdale, IL)

2011-05-17

377

Direct Observation of Ultrafast Non-thermal Melting by Ultrafast X-ray Diffraction  

Microsoft Academic Search

Ultrafast nonthermal melting of femtosecond laser-irradiated germanium was observed directly for the first time using sub-picosecond, 1.54-angstrom x-ray diffraction. Such measurements allow the study of transient atomic motion fundamental to many processes in physics, chemistry, and biology.

C. W. Siders; T. Guo; K. R. Wilson

378

Infrared imaging of temperature distribution in a high-temperature x-ray diffraction furnace  

Microsoft Academic Search

High Temperature X-ray Diffraction (HTXRD) is a very powerful tool for studies of reaction kinetics, phase transformations, and lattice thermal expansion of advanced materials. Accurate temperature measurement is a critical part of the technique. Traditionally, thermocouples, thermisters, and optical pyrometers have been used for temperature control and measurement, and temperature could only be measured at a single point. Infrared imaging

Hsin Wang; E. A. Payzant

1999-01-01

379

X-ray diffraction study of mineral components in calcareous algae (Corallinaceae, Rhodophyta)  

Microsoft Academic Search

The mineral composition of nine species of red calcareous algae (Corallinaceae, Rhodophyta) collected in the Adriatic Sea in 1987 and 1988 was examined by X-ray powder diffraction (counter diffractometer, monochromatized CuKa radiation). In addition, a comparison between the calcareous algae from the north Adriatic (Rovinj area) and the central Adriatic (Kornati Islands) with regard to genus, species and environmental factors

D. Medakovi?; S. Popovi?; N. Zavodnik; B. Gržeta; M. Plazonic

1995-01-01

380

Structural Order-Disorder Transformations Monitored by X-Ray Diffraction and Photoluminescence  

ERIC Educational Resources Information Center

A study was conducted to examine the structural order-disorder transformation promoted by controlled heat treatment using X-ray diffraction technique (XRD) and photoluminescence (PL) techniques as tools to monitor the degree of structural order. The experiment was observed to be versatile and easily achieved with low cost which allowed producing…

Lima, R. C.; Paris, E. C.; Leite, E. R.; Espinosa, J. W. M.; Souza, A. G.; Longo, E.

2007-01-01

381

KDP:Mn piezoelectric coefficients obtained by X-ray diffraction.  

PubMed

Crystals of pure potassium dihydrogen phosphate KH(2)PO(4) (KDP) and Mn-doped KDP (KDP:Mn) were grown from a water solution by the slow evaporation method and their piezoelectric properties were studied by X-ray diffraction methods. The results have shown an increase in the piezoelectric coefficients with the doping. PMID:20975229

Gomes, E J L; Moreira, S G C; de Menezes, A S; Dos Santos, A O; Pereira, D P; de Oliveira, P C; Remédios, C M R

2010-10-14

382

High energy white beam x-ray diffraction studies of residual strains in engineering components  

Microsoft Academic Search

In order to predict the durability of engineering components and improve performance, it is mandatory to understand residual stresses. The last decade has witnessed a significant increase of residual stress evaluation using diffraction of penetrating radiation, such as neutrons or high energy X-rays. They provide a powerful non-destructive method for determining the level of residual stresses in engineering components through

S. Y. Zhang; W. Vorster; T. S. Jun; X. Song; M. Golshan; D. Laundy; M. J. Walsh; A. M. Korsunsky

2008-01-01

383

The Structure of Vitreous Carbon from Wide Angle and Low Angle X-Ray Diffraction.  

National Technical Information Service (NTIS)

Both wide angle and low angle X-ray diffraction patterns have been measured for a sample of vitreous carbon which has been subjected to maximum heat-treatment of 1800C. The wide angle scattering was used to calculate a radial distribution function, which ...

C. J. Pings G. D. Wignall

1972-01-01

384

In situ x-ray diffraction measurements of the capillary fountain jet produced via ultrasonic atomization  

Microsoft Academic Search

In situ x-ray diffraction measurements were carried out for investigating the liquid structure in the ultrasonic fountain jet to consider the mechanism of the ``ultrasonic ethanol separation'' reported by Sato et al. [J. Chem. Phys. 114, 2382 (2001)]. For pure liquids (water and ethanol), it was found that the high frequency ultrasound does not affect the liquid structure microscopically. For

Yohko F. Yano; Junya Douguchi; Atsushi Kumagai; Takao Iijima; Yukinobu Tomida; Toshiaki Miyamoto; Kazuo Matsuura

2006-01-01

385

A high pressure cell for simultaneous osmotic pressure and x-ray diffraction measurements  

Microsoft Academic Search

In this paper, we report on a novel osmotic cell, developed to simultaneously subject a sample to osmotic stress and measure structural changes by small angle x-ray diffraction. The osmotic cell offers many advantages over more conventional methods of osmotically stressing soft materials to measure their structural response. In particular, a full osmotic analysis can be performed with a single

Béatrice L. L. E. Gauthé; Andrew J. Heron; John M. Seddon; Oscar Ces; Richard H. Templer

2009-01-01

386

Quantitative X-Ray Diffraction Mineralogy of Los Angeles Basin Core Samples.  

National Technical Information Service (NTIS)

This report contains X-ray diffraction (XRD) analysis of mineralogy for 81 sediment samples from cores taken from three drill holes in the Los Angeles Basin in 2000- 2001. We analyzed 26 samples from Pier F core, 29 from Pier C core, and 26 from the Webst...

J. R. Hein B. R. McIntyre B. D. Edwards O. I. Lakota

2006-01-01

387

Strain profiling of fatigue crack overload effects using energy dispersive X-ray diffraction  

Microsoft Academic Search

Synchrotron based energy dispersive X-ray diffraction has been used to profile the strains around fatigue cracks in 4140 steel test specimens. In particular strain field comparisons were made on specimens prepared: with initial constant stress intensity fatigue; with this initial fatigue followed by a single overload cycle; and with this fatigue-overload sequence followed by an additional constant stress intensity fatigue.

M. Croft; Z. Zhong; N. Jisrawi; I. Zakharchenko; R. L. Holtz; J. Skaritka; T. Fast; K. Sadananda; M. Lakshmipathy; T. Tsakalakos

2005-01-01

388

An Inquiry Based Exercise Using X-ray Diffraction Data to Incite Student Learning  

NASA Astrophysics Data System (ADS)

An inquiry based learning exercise was designed for an upper division advanced inorganic laboratory course that meets one of the requirements for the Bachelor of Science degree in Chemistry and Biochemistry at the University of California, Santa Cruz. The content goals of this exercise were evaluation of whether a given solid state structure was previously known by using powder X-ray diffraction data, and understanding how the diffraction pattern relates to the crystal structure of the compound in question. The scientific process goals included searching a database to match the patterns and preparing data for oral presentations. The goals of the exercise were addressed via an activity allowing students to utilize real X-ray powder diffraction data to search and match with known structures in a database (International Crystal Structure Database) and to give an oral presentation. After students found their structures in the database, they prepared oral presentations justifying their choice for the match and their reasoning through structural analysis of the X-ray data. Students learned about X-ray diffraction theory in an inquiry type environment and gained valuable experience and confidence in presenting their findings using strong reasoning and communication skills. Assessment was implemented during active facilitation throughout the activity and during the final oral presentations.

Rogow, D. L.; McDonald, W.; Bresler, M. R.

2010-12-01

389

Measurement of Whisker Orientation in Composites by X-Ray Diffraction.  

National Technical Information Service (NTIS)

Standard x-ray diffraction techniques have been shown to give a quantitative measure of orientation of alpha-SiC whiskers in polymeric matrices. The pole distributions of the (11-20) planes of SiC have been fitted to a normal bivariate distribution where ...

R. G. Schierding

1968-01-01

390

Transmission X-ray diffraction of single-crystal nickel-base superalloys  

SciTech Connect

Because of their superior high-temperature properties, monocrystalline nickel-base superalloys are used advantageously for turbine blades of modern gas turbines. During creep these alloys show changes in lattice parameters. These changes are dependent on temperature and stress. Transmission X-ray diffraction and regular Bragg reflection have been used to demonstrate these changes.

Biermann, H.; Von Grossmann, B. [Univ. Erlangen-Nuernberg, Erlangen (Germany). Inst. fuer Werkstoffwissenschaften

1999-07-01

391

A-DNA and B-DNA: Comparing Their Historical X-Ray Fiber Diffraction Images  

ERIC Educational Resources Information Center

|A-DNA and B-DNA are two secondary molecular conformations (among other allomorphs) that double-stranded DNA drawn into a fiber can assume, depending on the relative water content and other chemical parameters of the fiber. They were the first two forms to be observed by X-ray fiber diffraction in the early 1950s, respectively by Wilkins and…

Lucas, Amand A.

2008-01-01

392

X-ray and electron diffraction study of polyimide LB films  

NASA Astrophysics Data System (ADS)

The fabrication of polyimide LB films was carried out via two stages. The structure of polyimide LB films was studied by X-ray small-angle scattering and electron diffraction methods. It was shown that the macromolecules were packed into an orthorhombic lattice with unit cell parameters: a = 0.631, b = 0.397, c = 3.2 nm.

Yanusova, L. G.; Stiopina, N. D.; Klechkovskaya, V. V.; Feigin, L. A.; Baklagina, Yu. G.; Kudryavtsev, V. V.; Sklizkova, V. P.

1994-04-01

393

Diffractive lenses for photon energies ranging from the extreme ultraviolet to hard x rays  

NASA Astrophysics Data System (ADS)

Diffractive optics for the x-ray range have to meet the various requirements of experimental set-ups at synchrotron or other light sources. In the case of focusing elements it is essential that the devices are matched to parameters such as the photon energy and spatial coherence of the source, as well as the required spatial resolution, working distance, and diffraction efficiency. In some cases, a suppression of disturbing diffraction orders requires additional features such as an opaque central stop integrated into the lens. The Laboratory for Micro- and Nanotechnology provides the essential technologies necessary for the design and fabrication of diffractive x-ray lenses for a wide range of photon energies and applications. Over the past years, a large variety of optics tailored to the specific needs of x-ray optical experiments have been fabricated and tested. These include transmission Fresnel phase zone plate for microscopy, microprobe, or beam monitoring applications, as well as condensers to increase the flux in waveguiding experiments in the hard x-ray range. An overview of the nanofabrication technologies and a selection of experiments demonstrating the devices performance are presented.

David, Christian; Noehammer, Bernd; Solak, Harun H.; Haas, Bianca; Glaus, Fredy; van der Veen, J. Friso; Schlott, Volker; Bongaerts, Jeroen; Kaulich, Burkhard; Susini, Jean

2001-12-01

394

Computerized System for Quantitative X-Ray Diffraction Analysis of Pyrite in Coal.  

National Technical Information Service (NTIS)

The Bureau of Mines has developed a quantitative analysis for pyrite in coal by X-ray diffraction that can be accomplished in little more than 1 hour. To minimize the sample analysis time, data processing has been completely computerized with pertinent ou...

R. A. Friedel R. R. Schehl

1973-01-01

395

X-ray diffraction studies of polyaniline doped with Zn(NO3)2  

NASA Astrophysics Data System (ADS)

Polyaniline (PANI) and PANI/zinc nitrate composites were synthesized by in situ chemical oxidative polymerization of aniline with Zn(NO3)2 using ammonium peroxidisulphate (APS) as an oxidant. These composites were characterized by X-ray diffraction (XRD) and the results were compared with pure Polyaniline and zinc nitrate.

Goyal, Sneh Lata; Sharma, Smriti; Kumar, Devinder; Kishore, Nawal

2013-06-01

396

Three-dimensional imaging of dislocations by X-ray diffraction laminography  

SciTech Connect

Synchrotron radiation laminography with X-ray diffraction contrast enables three-dimensional imaging of dislocations in monocrystalline wafers. We outline the principle of the technique, the required experimental conditions, and the reconstruction procedure. The feasibility and the potential of the method are demonstrated by three-dimensional imaging of dislocation loops in an indent-damaged and annealed silicon wafer.

Haenschke, D. [Karlsruhe Institute of Technology (KIT), Laboratory for Applications of Synchrotron Radiation (LAS), 76128 Karlsruhe (Germany); Helfen, L. [Karlsruhe Institute of Technology (KIT), Institute for Photon Science and Synchrotron Radiation (IPS/ANKA), 76344 Eggenstein (Germany); European Synchrotron Radiation Facility (ESRF), BP220, 38043 Grenoble (France); Altapova, V. [Karlsruhe Institute of Technology (KIT), Laboratory for Applications of Synchrotron Radiation (LAS), 76128 Karlsruhe (Germany); National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Danilewsky, A. [University Freiburg, Kristallographie, Institut fuer Geowissenschaften, 79104 Freiburg (Germany); Baumbach, T. [Karlsruhe Institute of Technology (KIT), Laboratory for Applications of Synchrotron Radiation (LAS), 76128 Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute for Photon Science and Synchrotron Radiation (IPS/ANKA), 76344 Eggenstein (Germany)

2012-12-10

397

An x-ray diffraction study of zeolite-containing metal silicates  

SciTech Connect

An x-ray diffraction study of zeolites and zeolite-containing metal silicates showed that a reaction occurs in the preparation of zeolite-containing systems between the zeolite crystallites and the metal silicate base, which depends on the means of the introduction of the zeolite in the chemical composition of the base and the zeolite.

Mel'nikov, V.B.; Chukin, G.D.; Netedov, B.K.

1986-10-01

398

A wide-beam X-ray source suitable for diffraction enhanced imaging applications  

NASA Astrophysics Data System (ADS)

Research in diffraction-enhanced imaging (DEI), using a synchrotron source with an X-ray flux of 1.4×1012 ph/mm2/s, has shown strong potential in obtaining high-resolution images as compared to conventional radiographs. This research investigates the feasibility of developing a large area circular X-ray source with fluxes comparable to a synchrotron source. The source should be capable of integration into a compact system with peak powers not to exceed 200 kW to be feasible for use in a major medical facility, industrial complex or screening facility (such as cargo or airport). A computational study of a circular concentric filament wide-beam area X-ray source has been investigated in this research. The design features are based on generating electrons from three concentric circular filaments to provide an area electron flux, with a 60 kV accelerating potential and a beam current of up to 3 A. The X-ray target is a grounded stationary oxygen-free copper target with a layer of molybdenum. This target feature differs from standard rotating X-ray targets in conventional X-ray systems. Studies of electron trajectories and their distribution on the target were conducted using the SIMION 3D code. Heat loading and thermal management were studied using heat transfer modules from the coupled FEMLAB multi-physics and MATLAB codes. The Monte Carlo code MCNP 5 was used to obtain the X-ray flux and energy distribution for aluminum and beryllium windows. This computational study shows that this target configuration generates X-rays with photon flux comparable to synchrotron source and sufficient for DEI applications. The maximum target temperature rise is 1357 K after 70 s when cooling the back of the target to liquid nitrogen temperature using cold finger contact, and 325 K for an invaded target, in which liquid nitrogen circulates inside the target.

Kim, Chang H.; Bourham, Mohamed A.; Michael Doster, J.

2006-10-01

399

Study of palladium nanoparticles synthesized in alkali borosilicate glass pores by the X-ray line shift method  

NASA Astrophysics Data System (ADS)

Metallic Pd synthesized in porous glass with an average pore diameter of 7 ± 2 nm has been studied using the X-ray diffraction and X-ray line shift methods for the first time. The irregular dependence of the reflection width in X-ray patterns on the diffraction angle has been revealed. This can be caused by crystallite growth mostly in the [111] direction or by tetrahedral distortions of the fcc lattice. The shift (difference in energy) of K ?1 lines ( ?E ?1 = 19 ± 2 meV) for nanostructured Pd in comparison with the bulk material is first detected. The detected effect is considered within the assumption of the palladium electron redistribution between Pd 5 s- and 4 d-bands.

Sovestnov, A. E.; Naberezhnov, A. A.; Kumzerov, Yu. A.; Sysoeva, A. A.; Ganzha, V. A.; Egorov, A. I.; Okuneva, N. M.; Fedorov, V. I.; Fomin, E. V.

2013-04-01

400

Development of an x-ray diffraction camera used in magnetic fields up to 10 T  

SciTech Connect

A high-field x-ray diffraction (HF-XRD) camera was developed to observe structural changes of magnetic materials in magnetic fields up to 10 T. The instrument mainly consists of a Debye-Scherrer-type camera with a diameter of 80.1 mm, a 10-T cryocooled superconducting magnet with a 100-mm room-temperature bore, an x-ray source, a power supply, and a chiller for the x-ray source. An x-ray detector (image plate) in the HF-XRD camera can be taken out and inserted into the magnet without changing the sample position. The performance of the instrument was tested by measuring the HF-XRD for silicon and ferromagnetic MnBi powders. A change of x-ray diffraction pattern was observed due to the magnetic orientation of MnBi, showing that the instrument is useful for studying field-induced orientation processes and structural properties of field-controlled materials.

Mitsui, Yoshifuru; Takahashi, Kohki; Watanabe, Kazuo [High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Koyama, Keiichi [High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Graduate School for Science and Engineering, Kagoshima University, Kagoshima 890-0065 (Japan)

2011-12-15

401

Multivariate Data Analysis for Drug Identification Using Energy-Dispersive X-Ray Diffraction  

Microsoft Academic Search

Preliminary studies have shown the effectiveness of multivariate analysis (MVA) for drug identification from energy-dispersive X-ray diffraction patterns. A statistical model to predict drug content from the diffraction profile of a sample of mixed composition was developed by applying MVA to both experimental and simulated data. Separate data-sets were used for building and testing the models. Both experimental and simulated

Emily J. Cook; Silvia Pani; Leah George; Sheila Hardwick; Julie A. Horrocks; Robert D. Speller

2009-01-01

402

Coherent X-ray Diffraction Imaging for Strain Analysis on Single ZnO Nanorod  

NASA Astrophysics Data System (ADS)

Strain induced in nanostructure semiconductor materials can result in different electronic properties. Coherent x-ray diffraction (CXD) has emerged as a non-destructive tool for imaging of strain and defects. In this work CXD is applied on a single ZnO nanorod, diffraction patterns from Bragg reflection are used to reconstruct the strain distribution in the samples at a resolution of 40 nm.

Xiong, Gang; Leake, S.; Newton, M. C.; Huang, X.; Harder, R.; Robinson, Ian K.

2011-12-01

403

X-ray diffraction study of damage induced by swift heavy ion irradiation in fluorapatite  

Microsoft Academic Search

X-ray powder and high-resolution single-crystal diffraction techniques were used to study the irradiation damage of fluorapatites. Krypton, iodine and carbon irradiations were performed at high energy (?1MeV\\/a) in the 1011 to 5×1013cm?2 fluence range. Both diffraction techniques showed a strong unit-cell increase of the fluorapatite structure, with a full relaxation of the remaining part of the material for large fluences.

S. Miro; D. Grebille; D. Chateigner; D. Pelloquin; J.-P. Stoquert; J.-J. Grob; J.-M. Costantini; F. Studer

2005-01-01

404

Structure of Molten Copper-Antimony Alloys by Combination of Neutron and X-ray Diffraction  

Microsoft Academic Search

Diffraction experiments with 21 alloys from the system Cu-Sb were done by means of neutrons (1.19 Å) in transmission and by X-rays in reflection (Mo K?, ?H-?H goniometer). Corrections for neutron diffraction data are given and the RDF were calculated. Discussion of the nearest neighbours' distance rI and the coordination number z versus the concentration was done. With variation of

Walter Knoll; Siegfried Steeb

1973-01-01

405

Synchrotron X-Ray Diffraction Studies of Actin Structure during Polymerization  

Microsoft Academic Search

Synchrotron x-ray diffraction was used to identify the oligomers that formed during the earliest stages of actin polymerization. Solution diffraction patterns from G-actin (monomer) and from F-actin (polymer) contain information about the size and shape of actin monomers and the length, width, and subunit organization of filaments. Comparison of patterns collected during polymerization reveals an increase in scatter at spacings

Paul Matsudaira; Joan Bordas; M. H. J. Koch

1987-01-01

406

Synchrotron radiation energy-dispersive X-ray diffraction analysis of salt distribution in Lepine limestone  

Microsoft Academic Search

We describe an analytical application of synchrotron radiation energy-dispersive diffraction tomography to map the distribu- tion of crystalline sodium sulfate deposited by evaporation from solution within a building limestone. Few techniques are able to provide spatially-resolved analytical information from the interior of opaque objects. An important relatively recent development is the invention of energy-dispersive synchrotron X-ray diffraction tomography EDD-T.1,2 Ac

Ioannis Ioannou; William D. Hoff; Victoria A. Pugsleyb; Simon D. M. Jacquesd

407

Strain analysis by inversion of coherent Bragg X-ray diffraction intensity: the illumination problem  

Microsoft Academic Search

Bragg coherent X-ray diffraction imaging is demonstrated with a micro-focused illumination. The 2D projected density of the 3D nano-crystal is successfully retrieved from the inversion of its diffraction intensity pattern. The analysis of the phase field at the sample position, which holds in principle the strain information, emphasizes the high sensitivity of the technique with regard to the wavefront structure.

V. Chamard; M. Dollé; G. Baldinozzi; F. Livet; M. de Boissieu; S. Labat; F. Picca; C. Mocuta; P. Donnadieu; T. H. Metzger

2010-01-01

408

Single-crystal X-ray diffraction at high pressures with diamond-anvil cells  

Microsoft Academic Search

The past twenty years have seen the widespread development of diamond-anvil pressure cells (DAC's) suitable for carrying out single-crystal X-ray diffraction experiments to pressures in excess of 10 GPa. The relative advantages and disadvantages of the various types of DAC are discussed and the basic techniques for their operation, including pressure measurement and the collection of diffraction data, are described.

R. J. Angel; N. L. Ross; I. G. Wood; P. A. Woods

1992-01-01

409

Powder x-ray diffraction procedures for the Mound aging\\/surveillance program. [Lead styphnate; hexanitroazobenzene  

Microsoft Academic Search

Power x-ray diffraction procedures were developed and utilized for routine analysis of samples containing lead styphnate, hexanitroazobenzene and mixtures of titanium hydride and potassium perchlorate, in support of the aging\\/surveillance program at Mound. Diffraction data were collected with an automated Rigaku wide-angle powder diffractometer under remote control of a DEC PDP-11\\/44 computer that was connected to it with optical wave

D. B. Sullenger; E. F. Jendrek; B. L. Sorrell

1985-01-01

410

Internal strains and stresses measured in cortical bone via high-energy X-ray diffraction  

Microsoft Academic Search

High-energy synchrotron X-ray diffraction was used to study internal stresses in bone under in situ compressive loading. A transverse cross-section of a 12–14 year old beagle fibula was studied with 80.7keV radiation, and the transmission geometry was used to quantify internal strains and corresponding stresses in the mineral phase, carbonated hydroxyapatite. The diffraction patterns agreed with tabulated patterns, and the

J. D. Almer; S. R. Stock

2005-01-01

411

X-Ray Diffraction Instrument For In Situ Analysis of Martian Rocks  

NASA Astrophysics Data System (ADS)

The chemistry measured by XRF and APX during previous mission to Mars yielded rich information on certain aspects of Martian materials but cannot constrain the exact mineral assemblages and as a result, neither the genesis of the rocks or soils. For example, in some cases, a volcanic rock, a sedimentary rock, and a metamorphic rock can have the same chemical composition. Therefore in order to assess the Martian environment in which the rock or soil was produced, we need to perform analysis of the mineralogy of the material. For this purpose, we propose an X-Ray Instrument for Mineralogical Analysis of Planetary surface materials (XMAP) for Mars 2005 mission. Basically, XMAP will consist of an X-ray source, a sample holder and a CCD detector. The diffraction technique is based on the capability of atom lattices to diffract incident X-ray beams. The diffracted X-rays interfere each other and only the beams that interfere positively can reach the detector. The instrument may be also thought to be arranged for both a lander or a rover configuration with a few minor adaptive changes. XMAP will perform a no destructive analysis and a preparation of the sample is not required. We are planning to be able to discriminate a high range of minerals from clay or phyllosilicates, characterised by high interplanar lattice distance, to oxides and carbonates or evaporites. This rock spectrum is what we expect for exobiological exploration of Mars 2005 landing site. In addition, with XRD it is possible to identify the presence of water ice or dioxide ice; in fact, they give a different characteristic peak in the diffractometer spectrum. The same X-Ray source and detector for diffractometry analysis can be used for X-ray fluorescence combining the two methods and giving an accurate petrologic characterisation of rock sample.

Marinangeli, L.; Baliva, A.; Piluso, E.; Ori, G. G.; Casanova, I.; Lenti, A.; Ponzoni, C.; Cavazzutti, E.; Isabella, L.

1999-09-01

412

Analytic theory of soft x-ray diffraction by Lamellar Multilayer Gratings.  

PubMed

An analytic theory describing soft x-ray diffraction by Lamellar Multilayer Gratings (LMG) has been developed. The theory is derived from a coupled waves approach for LMGs operating in the single-order regime, where an incident plane wave can only excite a single diffraction order. The results from calculations based on these very simple analytic expressions are demonstrated to be in excellent agreement with those obtained using the rigorous coupled-waves approach. The conditions for maximum reflectivity and diffraction efficiency are deduced and discussed. A brief investigation into p-polarized radiation diffraction is also performed. PMID:21643171

Kozhevnikov, I V; van der Meer, R; Bastiaens, H M J; Boller, K-J; Bijkerk, F

2011-05-01

413

The energy calibration of x-ray absorption spectra using multiple-beam diffraction  

SciTech Connect

A new method for calibrating the energy scale of x-ray absorption spectra from an energy dispersive spectrometer has been developed. Distinct features in the diffracted intensity of the curved silicon crystal monochromator have been assigned to multiple-beam diffraction. The photon energies of these structures can be calculated if the precise spacing of the diffracting planes and the orientation of the crystal relative to the incident synchrotron radiation are known. The evaluation of Miller indices of operative reflections and the calculation of the corresponding photon energy is presented. The assignment of operative reflexes is simplified if the monochromator crystal can be rotated around the main diffracting vector {bold H}.

Hagelstein, M.; Cunis, S. (Fachhochschule Ostfriesland, Constantiaplatz 4, D-2970 Emden (Germany)); Frahm, R. (Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, Notkestrasse 85, D-2000 Hamburg 52 (Germany)); Rabe, P. (Fachhochschule Ostfriesland, Constantiaplatz 4, D-2970 Emden (Germany))

1992-01-01

414

X-ray multiple diffraction from crystalline multilayers: Application to a 90° Bragg reflection  

NASA Astrophysics Data System (ADS)

A generalized solution to the problem of multiple-beam dynamical x-ray diffraction from single and layered crystals with vertical strain is presented. The new formalism embraces all possible diffraction geometries, including extreme cases of grazing and normal incidence and emergence. The expressions for the diffracted wave amplitudes were obtained as recursion formulas. Numerical simulations were implemented and shown to be computationally stable. The formalism was successfully tested using experimental data obtained from a SiC/Si single-layered structure in a 90° diffraction geometry.

Souvorov, A.; Ishikawa, T.; Nikulin, A. Y.; Stetsko, Yuri P.; Chang, Shih-Lin; Zaumseil, P.

2004-12-01

415

A set-up for energy-dispersive X-ray diffraction measurements on weakly scattering (amorphous) materials  

Microsoft Academic Search

Describes the construction of a set-up for energy-dispersive X-ray diffraction measurements on weakly scattering (amorphous) samples. To minimise the effects of air scattering the diffraction chamber can be evacuated to pressures below 10 Pa. The set-up is fully radiation safe; the X-ray optics can be aligned by means of small DC-driven motors, while the X-ray beam is switched on. Some

W. Hoving; T. Egami; I. Vincze; F. van der Woude

1987-01-01

416

Fabrication of the 3 Dimension Resist Microstructure Using X-Ray Diffraction and Applying to LIGA Process  

NASA Astrophysics Data System (ADS)

The LIGA process consists of lithography, electroforming and molding has attracted attention in microstructure fabrication techniques. At the molding process of LIGA process, it is difficult to pull out from the mold that is assumed especially in the case of high aspect ratio structures. However, release from mold is improved by tapered structure. In this research, we have proposed a method for achieving tapered structure using the diffraction exposure technique which makes use of diffraction phenomenon. Diffraction is caused by providing a clearance between a resist structure and an X-ray mask. The fabricated structure was the lines and intermediate space whose processed depth was 200 µm and designated the taper angle of 5 degrees as set point. The variable parameters were the slit width, the X-ray dose and the gap between the X-ray mask and the resist structure. It is controlled that discovering the conditions for taper angle 5 degrees and inspecting the relationship between a taper angle and a mold releasability by electroforming and the molding of the LIGA process. We have fabricated the mold with taper angle of 2.5 degrees by electroforming. The Ni mold could partially copy the master pattern well.

Sawa, Yoshitaka; Tanabiki, Kyo; Noda, Daiji; Hattori, Tadashi

417

Femtosecond X-ray line emission from multilayer targets irradiated by short laser pulses  

Microsoft Academic Search

The invention of high-power, ultra-short-pulse lasers has opened the way to investigations aimed at the creation of a new type of bright X-ray source for various uses including material science applications and time-resolved X-ray diffraction for biology. The efficiency with which laser energy incident on a solid target is converted into an X-ray emission depends on many factors, including the

H. Nakano; A. A. Andreev; J. Limpouch

2004-01-01

418

Femtosecond x-ray line emission from specially designed targets irradiated by short laser pulses  

Microsoft Academic Search

The invention of high-power ultra short pulse lasers has opened way to investigations aimed at creation of a new type of bright x-ray source for different applications including material science and time resolved x-ray diffraction for biology. The conversion efficiency of the laser energy incident onto a solid target into the x-ray emission depends on many factors, including the temporal

Alexander A. Andreev; Hidetoshi Nakano; Jiri Limpouch

2004-01-01

419

Observation of Spin Helicity Using Nonresonant Circularly Polarized X-ray Diffraction Analysis  

NASA Astrophysics Data System (ADS)

We have successfully detected spin chirality in prototypical multiferroic MnWO4 wherein the helical magnetic order induces ferroelectricity using a nonresonant circularly polarized X-ray diffraction technique. The intensity of the magnetic reflection from MnWO4 shows a clear difference between the right- and left-handed circular polarizations of the incident X-ray beam. The ratio of these intensities is in good agreement with theoretical predictions. The results clearly show that this technique is suitable for the investigation of spin chirality. Finally, we studied the spin chirality of another multiferroic material, DyMnO3. Possible applications of this technique are also discussed.

Sagayama, Hajime; Abe, Nobuyuki; Taniguchi, Kouji; Arima, Taka-hisa; Yamasaki, Yuichi; Okuyama, Daisuke; Tokura, Yoshinori; Sakai, Souichiro; Morita, Takeshi; Komesu, Takashi; Ohsumi, Hiroyuki; Takata, Masaki

2010-04-01

420

Interaction between Lipid Monolayers and Poloxamer 188: An X-Ray Reflectivity and Diffraction Study  

PubMed Central

The mechanism by which poloxamer 188 (P188) seals a damaged cell membrane is examined using the lipid monolayer as a model system. X-ray reflectivity and grazing-incidence x-ray diffraction results show that at low nominal lipid density, P188, by physically occupying the available area and phase separating from the lipids, forces the lipid molecules to pack tightly and restore the barrier function of the membrane. Upon compression to bilayer equivalent pressure, P188 is squeezed out from the lipid monolayer, allowing a graceful exit of P188 when the membrane integrity is restored.

Wu, Guohui; Majewski, Jaroslaw; Ege, Canay; Kjaer, Kristian; Weygand, Markus Jan; Lee, Ka Yee C.

2005-01-01

421

Recover the phases from intensity data of x-ray diffraction  

NASA Astrophysics Data System (ADS)

For many years, people believed that in conventional x-ray crystallography one can only record the scattering intensities but not the phases. In order to study structures at the atomic scale, one has to use multibeam measurement or to rely on additional knowledge such as bonding length and to fit the intensity data by trial structure models. In this letter, however, we show that the phases are in fact hidden in the intensity data and can be recovered by studying the peak shoulders. To demonstrate, the x-ray diffraction data of aluminum powder were used to recover the phases and to reconstruct the electron density map.

Xu, Gu

1998-08-01

422

Reflection-mode x-ray powder diffraction cell for in situ studies of electrochemical reactions  

NASA Astrophysics Data System (ADS)

The design and operation of an electrochemical cell for reflection-mode powder x-ray diffraction experiments are discussed. The cell is designed for the study of electrodes that are used in rechargeable lithium batteries. It is designed for assembly in a glove box so that air-sensitive materials, such as lithium foil electrodes and carbonate-based electrolytes with lithium salts, can be used. The cell uses a beryllium window for x-ray transmission and electrical contact. A simple mechanism for compressing the electrodes is included in the design. Sample results for the cell are shown with a Cu K? source and a position-sensitive detector.

Roberts, G. A.; Stewart, K. D.

2004-05-01

423

X-ray wave guiding using three-beam Bragg-surface diffraction  

NASA Astrophysics Data System (ADS)

A diffraction-type of X-ray wave guide, in contrast to refraction-type, is proposed using three-beam diffraction geometry to generate a surface diffracted beam propagating along the direction of the wave guide. The three-beam Bragg-Surface diffraction involves a symmetric Bragg reflection and a surface diffraction. The former is used to guide a wide-angle incident beam into a silicon crystal. The simultaneously occurring surface diffraction then guides the diffracted beam propagating along the direction of the wave guide that is parallel to the crystal surface. A wave guide with a shallow ditch is then manufactured along the direction of the surface diffraction using the conventional lithographic technique. As a whole the wave guide consists of a three-layer structure of tantalum/photon resist (PMMA)/tantalum, on the Silicon substrate. The surface diffracted X-rays can then be confined in and guided along the layer of photon resist. Details of the design of the wave guide and synchrotron diffraction experiments will be reported.

Chang, Shih-Lin; Zheng, Yan-Zong

2012-02-01

424

Serial femtosecond X-ray diffraction of 30S ribosomal subunit microcrystals in liquid suspension at ambient temperature using an X-ray free-electron laser  

PubMed Central

High-resolution ribosome structures determined by X-ray crystallography have provided important insights into the mechanism of translation. Such studies have thus far relied on large ribosome crystals kept at cryogenic temperatures to reduce radiation damage. Here, the application of serial femtosecond X-ray crystallography (SFX) using an X-ray free-electron laser (XFEL) to obtain diffraction data from ribosome microcrystals in liquid suspension at ambient temperature is described. 30S ribosomal subunit microcrystals diffracted to beyond 6?Å resolution, demonstrating the feasibility of using SFX for ribosome structural studies. The ability to collect diffraction data at near-physiological temperatures promises to provide fundamental insights into the structural dynamics of the ribosome and its functional complexes.

Demirci, Hasan; Sierra, Raymond G.; Laksmono, Hartawan; Shoeman, Robert L.; Botha, Sabine; Barends, Thomas R. M.; Nass, Karol; Schlichting, Ilme; Doak, R. Bruce; Gati, Cornelius; Williams, Garth J.; Boutet, Sebastien; Messerschmidt, Marc; Jogl, Gerwald; Dahlberg, Albert E.; Gregory, Steven T.; Bogan, Michael J.

2013-01-01

425

Serial femtosecond X-ray diffraction of 30S ribosomal subunit microcrystals in liquid suspension at ambient temperature using an X-ray free-electron laser.  

PubMed

High-resolution ribosome structures determined by X-ray crystallography have provided important insights into the mechanism of translation. Such studies have thus far relied on large ribosome crystals kept at cryogenic temperatures to reduce radiation damage. Here, the application of serial femtosecond X-ray crystallography (SFX) using an X-ray free-electron laser (XFEL) to obtain diffraction data from ribosome microcrystals in liquid suspension at ambient temperature is described. 30S ribosomal subunit microcrystals diffracted to beyond 6?Å resolution, demonstrating the feasibility of using SFX for ribosome structural studies. The ability to collect diffraction data at near-physiological temperatures promises to provide fundamental insights into the structural dynamics of the ribosome and its functional complexes. PMID:23989164

Demirci, Hasan; Sierra, Raymond G; Laksmono, Hartawan; Shoeman, Robert L; Botha, Sabine; Barends, Thomas R M; Nass, Karol; Schlichting, Ilme; Doak, R Bruce; Gati, Cornelius; Williams, Garth J; Boutet, Sébastien; Messerschmidt, Marc; Jogl, Gerwald; Dahlberg, Albert E; Gregory, Steven T; Bogan, Michael J

2013-08-19

426

Thermal transport in thin films measured by time-resolved, grazing incidence x-ray diffraction.  

SciTech Connect

We use depth- and time-resolved x-ray diffraction to study thermal transport across single crystal Bi films grown on sapphire in order to determine the thermal conductivity of the film and the Kapitza conductance of the interface. Ultrafast Ti:sapphire laser pulses were used to heat the films; x-ray diffraction then measured the film's lattice expansion. Use of grazing incidence diffraction geometry provided depth sensitivity, as the x-ray angle of incidence was varied near the critical angle. The shift of the film's Bragg peak position with time was used to determine the film temperature averaged over an x-ray penetration depth that could be selected by choice of the angle of incidence. For films that were thick compared to the laser penetration depth, we observed a large temperature gradient at early times. In this case, measurements with the incident angle near or well above the critical angle were more sensitive to the film conductivity or Kapitza conductance, respectively. For thinner films, however, cooling was dominated by the Kapitza conductance at all accessible time scales.

Walko, D. A.; Sheu, Y.-M.; Trigo, M.; Reis, D. A. (X-Ray Science Division); (Univ. of Michigan,); (SLAC National Accelerator Lab.); (Stanford Univ.)

2011-01-01

427

Cyclic olefin homopolymer-based microfluidics for protein crystallization and in situ X-ray diffraction  

PubMed Central

Microfluidics is a promising technology for the rapid iden­tification of protein crystallization conditions. However, most of the existing systems utilize silicone elastomers as the chip material which, despite its many benefits, is highly permeable to water vapour. This limits the time available for protein crystallization to less than a week. Here, the use of a cyclic olefin homopolymer-based microfluidics system for protein crystallization and in situ X-ray diffraction is described. Liquid handling in this system is performed in 2?mm thin transparent cards which contain 500 chambers, each with a volume of 320?nl. Microbatch, vapour-diffusion and free-interface diffusion protocols for protein crystallization were implemented and crystals were obtained of a number of proteins, including chicken lysozyme, bovine trypsin, a human p53 protein containing both the DNA-binding and oligomerization domains bound to DNA and a functionally important domain of Arabidopsis Morpheus’ molecule 1 (MOM1). The latter two polypeptides have not been crystallized previously. For X-ray diffraction analysis, either the cards were opened to allow mounting of the crystals on loops or the crystals were exposed to X-rays in situ. For lysozyme, an entire X-ray diffraction data set at 1.5?Å resolution was collected without removing the crystal from the card. Thus, cyclic olefin homopolymer-based microfluidics systems have the potential to further automate protein crystallization and structural genomics efforts.

Emamzadah, Soheila; Petty, Tom J.; De Almeida, Victor; Nishimura, Taisuke; Joly, Jacques; Ferrer, Jean-Luc; Halazonetis, Thanos D.

2009-01-01

428

A laboratory based system for Laue micro x-ray diffraction  

SciTech Connect

A laboratory diffraction system capable of illuminating individual grains in a polycrystalline matrix is described. Using a microfocus x-ray source equipped with a tungsten anode and prefigured monocapillary optic, a micro-x-ray diffraction system with a 10 mum beam was developed. The beam profile generated by the ellipsoidal capillary was determined using the"knife edge" approach. Measurement of the capillary performance, indicated a beam divergence of 14 mrad and a useable energy bandpass from 5.5 to 19 keV. Utilizing the polychromatic nature of the incident x-ray beam and application of the Laue indexing software package X-Ray Micro-Diffraction Analysis Software, the orientation and deviatoric strain of single grains in a polycrystalline material can be studied. To highlight the system potential the grain orientation and strain distribution of individual grains in a polycrystalline magnesium alloy (Mg 0.2 wt percent Nd) was mapped before and after tensile loading. A basal (0002) orientation was identified in the as-rolled annealed alloy; after tensile loading some grains were observed to undergo an orientation change of 30 degrees with respect to (0002). The applied uniaxial load was measured as an increase in the deviatoric tensile strain parallel to the load axis (37 References).

Advanced Light Source; Tamura, Nobumichi; Lynch, P.A.; Stevenson, A.W.; Liang, D.; Parry, D.; Wilkins, S.; Tamura, N.

2007-02-28

429

The catalytic mechanism of an aspartic proteinase explored with neutron and X-ray diffraction  

SciTech Connect

Hydrogen atoms play key roles in enzyme mechanism, but as this study shows, even high-quality X-ray data to a resolution of 1 {angstrom} cannot directly visualize them. Neutron diffraction, however, can locate deuterium atoms even at resolutions around 2 {angstrom}. Both neutron and X-ray diffraction data have been used to investigate the transition state of the aspartic proteinase endothiapepsin. The different techniques reveal a different part of the story, revealing the clearest picture yet of the catalytic mechanism by which the enzyme operates. Room temperature neutron and X-ray diffraction data were used in a newly developed joint refinement software package to visualize deuterium atoms within the active site of the enzyme when a gem-diol transition state analogue inhibitor is bound at the active site. These data were also used to estimate their individual occupancy, while analysis of the differences between the bond lengths of the catalytic aspartates was performed using atomic resolution X-ray data. The two methods are in agreement on the protonation state of the active site with a transition state analogue inhibitor bound confirming the catalytic mechanism at which the enzyme operates.

Kovalevsky, Andrey [Los Alamos National Laboratory (LANL); Erskine, Peter T. [University of Southampton, England; Cooper, Jon [University of Southampton, England

2008-01-01

430

An X-ray photoelectron diffraction study of a TiO 2(001) anatase single crystal mineral  

Microsoft Academic Search

An anatase single crystal mineral is examined with low energy electron diffraction, X-ray photoelectron spectroscopy and X-ray photoelectron diffraction. Different gasses (He or Ar) are used to clean the sample and their influence on the azimuthal XPD curves is checked. Azimuthal scans for the polar angles 15, 28 and 51° off surface are recorded. Experimental data are compared with single

G. Silversmit; H. Poelman; L. Fiermans; R. De Gryse

2001-01-01

431

New method for calculating the intensities of X rays and thermal neutrons diffracted in single crystals with defects  

SciTech Connect

A new method is proposed to calculate the intensities of X rays and thermal neutrons diffracted in single crystals with defects. This method is based on comparing the dynamic theory of the Bragg diffraction of X rays and thermal neutrons in perfect single crystals with the small-angle scattering theory.

Egiazaryan, A. M.; Gevorkyan, K. M., E-mail: konstantin@iapp.sci.am; Atanesyan, A. K. [National Academy of Sciences of the Republic of Armenia, Institute of Applied Problems of Physics (Armenia)

2011-05-15

432

A regularized iterative reconstruction algorithm for x-ray diffraction tomography  

NASA Astrophysics Data System (ADS)

Material discrimination based on conventional or dual energy X-ray computed tomography (CT) imaging can be ambiguous. X-ray diraction imaging (XDI) can be used to construct diraction proles of objects, providing molecular signature information that can be used to characterize the presence of specic materials. Combining X-ray CT and diraction imaging can lead to enhanced detection and identication of explosives in luggage screening. Current XDI scan systems are based on direct imaging rather than tomographic imaging, which require the use of line collimators to localize scattering location and thus result in slow scan performance. In an eort to gain faster scan times and better signal-to-noise ratio, we focus on tomographic inversion techniques for X-ray Diraction Tomography (XDT) and look for joint reconstruction of CT absorption and X-ray diraction prole images of object. We present a fast reconstruction algorithm with geometric feature preserving regularization (IREP) using image-wise based iterative coordinate descent (ICD).We validate the initial results via Monte Carlo simulation of X-ray absorption and coherent scattering in 2 dimensions (2D), and compare the performance of the IREP algorithm with existing inversion techniques such as the ltered backprojection method and the algebraic reconstruction technique. The experimental results show that the IREP method oers improved image quality for enhanced material identication.

Chen, Ke; Castañón, David A.

2012-05-01

433

Quantitative comparison of imaging performance of x-ray interferometric imaging and diffraction enhanced imaging  

SciTech Connect

For detailed biomedical observations using the optimum phase-contrast x-ray imaging, quantitative comparisons of imaging performances of two major imaging methods--x-ray interferometric imaging (XII) and diffraction enhanced imaging (DEI)--were performed. Density sensitivity and spatial resolution of each imaging method were evaluated using phantom tomograms obtained by each method with the same x-ray dosage. For practical comparison of the methods, biological samples were also observed under the same conditions. The results show that XII has a higher sensitivity than that of DEI and is thus suitable for observation of soft biological tissues. On the other hand, DEI has a wider dynamic range of density and is thus suitable for observation of samples with large differences in density of different regions.

Akio, Yoneyama; Jin, Wu; Kazuyuki, Hyodo; Tohoru, Takeda [Advanced Research Laboratory, Hitachi, Ltd., 2520 Akanuma, Hatoyama, Saitama, 350-0395 (Japan); Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8575 (Japan); Institute of Materials Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki, 305-0801 (Japan); Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8575 (Japan)

2008-10-15

434

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

SciTech Connect

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

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

2007-01-19

435

Coherent hard x-ray diffractive imaging of nonisolated objects confined by an aperture  

SciTech Connect

Coherent hard x-ray imaging of nonisolated weak phase objects is demonstrated by confining x-ray beam in a region of a few micrometers in cross section using a micrometer-sized aperture. Two major obstacles in the hard x-ray coherent diffraction imaging, isolating samples and obtaining central speckles, are addressed by using the aperture. The usefulness of the proposed method is illustrated by reconstructing the exit wave field of a nanoscale trench structure fabricated on silicon which serves as a weak phase object. The quantitative phase information of the exit wave field was used to reconstruct the depth profile of the trench structure. The scanning capability of this method was also briefly discussed.

Kim, Sunam; Kim, Chan; Lee, Suyong; Marathe, Shashidhara; Noh, D. Y.; Kang, H. C.; Kim, S. S.; Sandy, A.; Narayanan, S. [Department of Materials Science and Engineering and Nanobio Materials and Electronics, Graduate Program of Photonics and Applied Physics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Department of Advanced Materials Engineering and BK21 Education Center of Mould Technology for Advanced Materials and Parts, Chosun University, Gwangju 501-759 (Korea, Republic of); Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2010-04-15

436

A geometry for sub-nanosecond X-ray diffraction from laser-shocked polycrystalline foils  

SciTech Connect

In situ picosecond X-ray diffraction has proved to be a useful tool in furthering our understanding of the response of shocked crystals at the lattice level. To date the vast majority of this work has used single crystals as the shocked samples, owing to their diffraction efficiency, although the study of the response of polycrystalline samples is clearly of interest for many applications. We present here the results of experiments to develop sub-nanosecond powder/polycrystalline diffraction using a cylindrical pinhole camera. By allowing the incident X-ray beam to impinge on the sample at non-normal angles, the response of grains making a variety of angles to the shock propagation direction can potentially be interrogated.

Wark, Justin; Higginbotham, Andrew; Kimminau, Giles; Murphy, William; Nagler, Bob; Whitcher, Thomas [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom); Hawreliak, James; Kalantar, Dan; Butterfield, Martin; El-Dasher, Bassem; McNaney, James; Milathianaki, Despina; Lorenzana, Hector; Remington, Bruce [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Davies, Huw; Thornton, Lee; Park, Nigel [AWE, Aldermaston (United Kingdom); Lukezic, Stan

2007-12-12

437

Single-particle structure determination by correlations of snapshot X-ray diffraction patterns  

NASA Astrophysics Data System (ADS)

Diffractive imaging with free-electron lasers allows structure determination from ensembles of weakly scattering identical nanoparticles. The ultra-short, ultra-bright X-ray pulses provide snapshots of the randomly oriented particles frozen in time, and terminate before the onset of structural damage. As signal strength diminishes for small particles, the synthesis of a three-dimensional diffraction volume requires simultaneous involvement of all data. Here we report the first application of a three-dimensional spatial frequency correlation analysis to carry out this synthesis from noisy single-particle femtosecond X-ray diffraction patterns of nearly identical samples in random and unknown orientations, collected at the Linac Coherent Light Source. Our demonstration uses unsupported test particles created via aerosol self-assembly, and composed of two polystyrene spheres of equal diameter. The correlation analysis avoids the need for orientation determination entirely. This method may be applied to the structural determination of biological macromolecules in solution.

Starodub, D.; Aquila, A.; Bajt, S.; Barthelmess, M.; Barty, A.; Bostedt, C.; Bozek, J. D.; Coppola, N.; Doak, R. B.; Epp, S. W.; Erk, B.; Foucar, L.; Gumprecht, L.; Hampton, C. Y.; Hartmann, A.; Hartmann, R.; Holl, P.; Kassemeyer, S.; Kimmel, N.; Laksmono, H.; Liang, M.; Loh, N. D.; Lomb, L.; Martin, A. V.; Nass, K.; Reich, C.; Rolles, D.; Rudek, B.; Rudenko, A.; Schulz, J.; Shoeman, R. L.; Sierra, R. G.; Soltau, H.; Steinbrener, J.; Stellato, F.; Stern, S.; Weidenspointner, G.; Frank, M.; Ullrich, J.; Strüder, L.; Schlichting, I.; Chapman, H. N.; Spence, J. C. H.; Bogan, M. J.

2012-12-01

438

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

439

Direct modeling of X-ray diffraction pattern from contracting skeletal muscle.  

PubMed

A direct modeling approach was used to quantitatively interpret the two-dimensional x-ray diffraction patterns obtained from contracting mammalian skeletal muscle. The dependence of the calculated layer line intensities on the number of myosin heads bound to the thin filaments, on the conformation of these heads and on their mode of attachment to actin, was studied systematically. Results of modeling are compared to experimental data collected from permeabilized fibers from rabbit skeletal muscle contracting at 5 degrees C and 30 degrees C and developing low and high isometric tension, respectively. The results of the modeling show that: i), the intensity of the first actin layer line is independent of the tilt of the light chain domains of myosin heads and can be used as a measure of the fraction of myosin heads stereospecifically attached to actin; ii), during isometric contraction at near physiological temperature, the fraction of these heads is approximately 40% and the light chain domains of the majority of them are more perpendicular to the filament axis than in rigor; and iii), at low temperature, when isometric tension is low, a majority of the attached myosin heads are bound to actin nonstereospecifically whereas at high temperature and tension they are bound stereospecifically. PMID:18539638

Koubassova, Natalia A; Bershitsky, Sergey Y; Ferenczi, Michael A; Tsaturyan, Andrey K

2008-06-06

440

Core-level X-ray photoelectron spectra and X-ray photoelectron diffraction of RuO 2(110) grown by molecular beam epitaxy on TiO 2(110)  

Microsoft Academic Search

We have measured Ru 3d, 4s, 4p and O 1s high-resolution core-level X-ray photoelectron spectra, along with Ru 3d and O 1s scanned-angle X-ray photoelectron diffraction angular distributions, for RuO2(110). The surfaces were prepared by oxygen-plasma-assisted molecular beam epitaxial growth of RuO2 on TiO2(110). XPS spectral interpretation and the nature of the XPD scans strongly suggest that the complex line

Y. J. Kim; Y. Gao; S. A. Chambers

1997-01-01

441

Strain and shape analysis of multilayer surface gratings by coplanar and by grazing-incidence x-ray diffraction  

Microsoft Academic Search

The surface shape and the spatial distribution of strain in GaInAs\\/InP multilayer gratings is experimentally determined by combining high-resolution x-ray diffraction and grazing-incidence diffraction. Dramatic deformations of the diffraction patterns in the measured reciprocal space maps of such gratings indicate a strongly nonuniform character of lattice distortions in the layers, caused by elastic strain relaxation. By coupling x-ray diffraction theory

T. Baumbach; D. Lübbert; M. Gailhanou

2000-01-01

442

X-ray in-line phase retrieval for tomography  

NASA Astrophysics Data System (ADS)

Phase contrast in X-ray imaging offers imaging of fine features at lower doses than absorption. Of the phasecontrast methods in use in-line phase contrast is interesting due to its experimental simplicity, but to extract information on absorption and phase distributions from the resulting images, phase retrieval is needed. Many phase-retrieval methods suitable for different situations have been developed, but few comparisons of those methods done. We consider a sub-group of phase-retrieval methods that are suitable for tomography, i.e., that use only one exposure (for practical experimental reasons) and are non-iterative (for speed). In total we have found seven suitable methods in the literature. All, though derived in different ways under different assumptions, follow the same pattern and can be outlined as a single method where each specific version is marked by variations in particular steps. We summarize this unified approach, and give the variations of the individual methods. In addition, we outline approximations and assumptions of each method. Using this approach it is possible to conclude which specific algorithms are most suitable in specific situations and to test this based on simulated and experimental data. Ultimately, this leads to conclusions on which methods are the most suitable in different situations.

Burvall, Anna; Lundström, Ulf; Takman, Per A. C.; Larsson, Daniel H.; Hertz, Hans M.

2012-02-01

443

Self-terminating diffraction gates femtosecond X-ray nanocrystallography measurements  

PubMed Central

X-ray free-electron lasers have enabled new approaches to the structural determination of protein crystals that are too small or radiation-sensitive for conventional analysis1. For sufficiently short pulses, diffraction is collected before significant changes occur to the sample, and it has been predicted that pulses as short as 10 fs may be required to acquire atomic-resolution structural information1–4. Here, we describe a mechanism unique to ultrafast, ultra-intense X-ray experiments that allows structural information to be collected from crystalline samples using high radiation doses without the requirement for the pulse to terminate before the onset of sample damage. Instead, the diffracted X-rays are gated by a rapid loss of crystalline periodicity, producing apparent pulse lengths significantly shorter than the duration of the incident pulse. The shortest apparent pulse lengths occur at the highest resolution, and our measurements indicate that current X-ray free-electron laser technology5 should enable structural determination from submicrometre protein crystals with atomic resolution.

Barty, Anton; Caleman, Carl; Aquila, Andrew; Timneanu, Nicusor; Lomb, Lukas; White, Thomas A.; Andreasson, Jakob; Arnlund, David; Bajt, Sasa; Barends, Thomas R. M.; Barthelmess, Miriam; Bogan, Michael J.; Bostedt, Christoph; Bozek, John D.; Coffee, Ryan; Coppola, Nicola; Davidsson, Jan; DePonte, Daniel P.; Doak, R. Bruce; Ekeberg, Tomas; Elser, Veit; Epp, Sascha W.; Erk, Benjamin; Fleckenstein, Holger; Foucar, Lutz; Fromme, Petra; Graafsma, Heinz; Gumprecht, Lars; Hajdu, Janos; Hampton, Christina Y.; Hartmann, Robert; Hartmann, Andreas; Hauser, Gunter; Hirsemann, Helmut; Holl, Peter; Hunter, Mark S.; Johansson, Linda; Kassemeyer, Stephan; Kimmel, Nils; Kirian, Richard A.; Liang, Mengning; Maia, Filipe R. N. C.; Malmerberg, Erik; Marchesini, Stefano; Martin, Andrew V.; Nass, Karol; Neutze, Richard; Reich, Christian; Rolles, Daniel; Rudek, Benedikt; Rudenko, Artem; Scott, Howard; Schlichting, Ilme; Schulz, Joachim; Seibert, M. Marvin; Shoeman, Robert L.; Sierra, Raymond G.; Soltau, Heike; Spence, John C. H.; Stellato, Francesco; Stern, Stephan; Struder, Lothar; Ullrich, Joachim; Wang, X.; Weidenspointner, Georg; Weierstall, Uwe; Wunderer, Cornelia B.; Chapman, Henry N.

2013-01-01

444

X-ray spectral line coincidences between fluorine VIII (and IX) and transition metal lines  

SciTech Connect

X-ray spectroscopy was performed in the 12 to 15 A region, recording L-shell lines from selected laser-irradiated transition metals. Line coincidences and near coincidences were identified between Fe, Cr, Mn, and Ni L-spectra, and F VIII and F IX K-shell lines. Wavelengths were determined to accuracies of 1 to 3 mA and will be utilized in selecting potential pumping candidates in future x-ray lasing schemes. High-resolution x-ray spectra were collected under controlled illumination and target conditions using 1.05 ..mu..m and 0.527 ..mu..m laser excitation with the KMS CHROMA laser.

Charatis, G.; Rockett, P.D.; Burkhalter, P.G.

1983-01-01

445

High resolution x-ray diffraction methodology for the structural analysis of one-dimensional nanostructures  

NASA Astrophysics Data System (ADS)

We present a systematic high-resolution x-ray diffraction (HRXRD) methodology for the analysis of one-dimensional nanostructures, in order to give answer to some of the frequently found problems in the literature. Regarding the assessment of structural properties, it is well known that high resolution x-ray diffraction measurements can provide qualitative and quantitative information on several intrinsic parameters of the material. However when nanostructures are present, the difficulties in analyzing the diffracted signals coming from nanostructures and the homolayer on which they usually grow have led to a reduced use of this technique, one of the most powerful methods for structural analysis. The aim of this paper is to develop a methodology for the analysis of one-dimensional structures based on the mosaic model similar to the one used in the x-ray diffraction methods for layers and films. On this basis, it has been possible by making a careful and systematic application of HRXRD to obtain separated structural information of nanostructures and the layer/block/grain underneath. In addition, the existence of a long-range ordering of nanostructures has been studied from the detection and analysis of forbidden reflections. The HRXRD experimental work has been particularized on ZnO nanorods grown by catalyst-free metal organic chemical deposition on c-sapphire substrates.

Martínez-Tomás, M. C.; Montenegro, D. N.; Sallet, V.; Muñoz-Sanjosé, V.

2012-07-01

446

Picosecond calorimetry: time-resolved x-ray diffraction studies of liquid CH2Cl2.  

PubMed

Liquid phase time-resolved x-ray diffraction with 100 ps resolution has recently emerged as a powerful technique for probing the structural dynamics of transient photochemical species in solution. It is intrinsic to the method, however, that a structural signal is observed not only from the photochemical of interest but also from the embedding solvent matrix. To experimentally characterize the x-ray diffraction signal deriving from the solvent alone we performed time-resolved diffraction studies of a pure liquid sample over a time domain from -250 ps to 2.5 micros. Multiphoton excitation was used to rapidly heat liquid CH(2)Cl(2) using UV pulses of 100 fs duration. A significant x-ray diffraction signal is visible prior to the onset of thermal expansion, which characterizes a highly compressed superheated liquid. Liquid CH(2)Cl(2) then expands as a shock wave propagates through the sample and the temporal dependence of this phenomenon is in good agreement with theory. An unexpectedly slow initial release of energy into the liquid as heat is observed from multiphoton excited CH(2)Cl(2), revealing the presence of a metastable state of multiphoton excited CH(2)Cl(2). PMID:16821929

Georgiou, Panayiotis; Vincent, Jonathan; Andersson, Magnus; Wöhri, Annemarie B; Gourdon, Pontus; Poulsen, Jens; Davidsson, Jan; Neutze, Richard

2006-06-21

447

X-ray diffraction imaging of metal-oxide epitaxial tunnel junctions made by optical lithography: use of focused and unfocused X-ray beams.  

PubMed

X-ray diffraction techniques are used in imaging mode in order to characterize micrometre-sized objects. The samples used as models are metal-oxide tunnel junctions made by optical lithography, with lateral sizes ranging from 150 µm down to 10 µm and various shapes: discs, squares and rectangles. Two approaches are described and compared, both using diffraction contrast: full-field imaging (topography) and raster imaging (scanning probe) using a micrometre-sized focused X-ray beam. It is shown that the full-field image gives access to macroscopic distortions (e.g. sample bending), while the local distortions, at the micrometre scale (e.g. tilts of the crystalline planes in the vicinity of the junction edges), can be accurately characterized only using focused X-ray beams. These local defects are dependent on the junction shape and larger by one order of magnitude than the macroscopic curvature of the sample. PMID:23412494

Mocuta, Cristian; Barbier, Antoine; Stanescu, Stefan; Matzen, Sylvia; Moussy, Jean Baptiste; Ziegler, Eric

2013-01-19

448

X-ray Diffraction Studies of the Thick Filament in Permeabilized Myocardium from Rabbit  

SciTech Connect

Low angle x-ray diffraction patterns from relaxed permeabilized rabbit cardiac trabeculae and psoas muscle fibers were compared. Temperature was varied from 25{sup o}C to 5{sup o}C at 200 mM and 50 mM ionic strengths ({mu}), respectively. Effects of temperature and {mu} on the intensities of the myosin layer lines (MLL), the equatorial intensity ratio I{sub 1,1}/I{sub 1,0}, and the spacing of the filament lattice are similar in both muscles. At 25{sup o}C, particularly at {mu} = 50 mM, the x-ray patterns exhibited up to six orders of MLL and sharp meridional reflections, signifying that myosin heads (cross-bridges) are distributed in a well-ordered helical array. Decreasing temperature reduced MLL intensities but increased I{sub 1,1}/I{sub 1,0}. Decreases in the MLL intensities indicate increasing disorder in the distribution of cross-bridges on the thick filaments surface. In the skeletal muscle, order/disorder is directly correlated with the hydrolysis equilibrium of ATP by myosin, [M.ADP.P{sub i}]/[M.ATP]. Similar effects of temperature on MLL and similar biochemical ATP hydrolysis pathway found in both types of muscles suggest that the order/disorder states of cardiac cross-bridges may well be correlated with the same biochemical and structural states. This implies that in relaxed cardiac muscle under physiological conditions, the unattached cross-bridges are largely in the M.ADP.P{sub i} state and with the lowering of the temperature, the equilibrium is increasingly in favor of [M.ATP] and [A.M.ATP]. There appear to be some differences in the diffraction patterns from the two muscles, however. Mainly, in the cardiac muscle, the MLL are weaker, the I{sub 1,1}/I{sub 1,0} ratio tends to be higher, and the lattice spacing D{sub 10}, larger. These differences are consistent with the idea that under a wide range of conditions, a greater fraction of cross-bridges is weakly bound to actin in the myocardium.

Xu,S.; Martyn, D.; Zaman, J.; Yu, L.

2007-01-01

449

X-ray Diffraction Studies of the Thick Filament in Permeabilized Myocardium from Rabbit  

SciTech Connect

Low angle x-ray diffraction patterns from relaxed permeabilized rabbit cardiac trabeculae and psoas muscle fibers were compared. Temperature was varied from 25{sup o}C to 5{sup o}C at 200 mM and 50 mM ionic strengths ({mu}), respectively. Effects of temperature and {mu} on the intensities of the myosin layer lines (MLL), the equatorial intensity ratio I{sub 1,1}/I{sub 1,0}, and the spacing of the filament lattice are similar in both muscles. At 25{sup o}C, particularly at {mu} = 50 mM, the x-ray patterns exhibited up to six orders of MLL and sharp meridional reflections, signifying that myosin heads (cross-bridges) are distributed in a well-ordered helical array. Decreasing temperature reduced MLL intensities but increased I{sub 1,1}/I{sub 1,0}. Decreases in the MLL intensities indicate increasing disorder in the distribution of cross-bridges on the thick filaments surface. In the skeletal muscle, order/disorder is directly correlated with the hydrolysis equilibrium of ATP by myosin, [M.ADP.P{sub i}]/[M.ATP]. Similar effects of temperature on MLL and similar biochemical ATP hydrolysis pathway found in both types of muscles suggest that the order/disorder states of cardiac cross-bridges may well be correlated with the same biochemical and structural states. This implies that in relaxed cardiac muscle under physiological conditions, the unattached cross-bridges are largely in the M.ADP.P{sub i} state and with the lowering of the temperature, the equilibrium is increasingly in favor of [M.ATP] and [A.M.ATP]. There appear to be some differences in the diffraction patterns from the two muscles, however. Mainly, in the cardiac muscle, the MLL are weaker, the I{sub 1,1}/I{sub 1,0} ratio tends to be higher, and the lattice spacing D{sub 10}, larger. These differences are consistent with the idea that under a wide range of conditions, a greater fraction of cross-bridges is weakly bound to actin in the myocardium.

Xu,S.; Martyn, D.; Zaman, J.; Yu, L.

2006-01-01

450

Prediction of Elastic Modulus + Anisotropy Using X-Ray and Electron Backscattered Diffraction Texture Quantification and Ultrasonic (Electromagnetic Acoustic Transducer) Measurements in Aluminum Sheets  

NASA Astrophysics Data System (ADS)

Crystallographic texture is generally measured using X-ray diffraction, performed off-line using small samples determining near-surface texture only; electron backscattered diffraction (EBSD) can also be used, but only samples relatively small areas. Ultrasonic methods determine elastic property anisotropy and texture, via orientation distribution coefficients (ODCs), and while there is substantial literature comparing ultrasonically determined properties with X-ray or neutron diffraction texture, there is little discussion about texture inhomogeneity (place to place in a sheet or through thickness) and sampling volume effects (X-ray compared to EBSD) on the accuracy of the correlations. In this article, the crystallographic texture of nominally pure aluminum and commercial aluminum alloy sheets has been determined by X-ray diffraction and EBSD and used to calculate the elastic anisotropy, which is then compared to ultrasonic electromagnetic acoustic transducer (EMAT) velocity anisotropy taking into account through-thickness texture variations. Significant and consistent spatial variability in texture occurs in the aluminum sheet samples (sheet edge to center and through thickness). Predictions of elastic anisotropy based on surface texture determination, as characterized by X-ray diffraction or surface EBSD, gave poor correlations with EMAT velocity anisotropy when the sample contained significant through thickness texture variations; however, accounting for this using multiple EBSD scans through thickness gave good correlations.

Davis, C. L.; Strangwood, M.; Potter, M.; Dixon, S.; Morris, P. F.

2008-03-01

451

Study of X-ray Weakness among Luminous Narrow-line Quasars  

NASA Astrophysics Data System (ADS)

The unusual properties of Narrow-line Seyfert 1 galaxies (NLS1s) are thought to result from a higher accretion rate relative to Eddington than broad-line Seyferts. Luminous NLS1s should have the highest accretion rates of all. With our recent study, several X-ray weak objects were found, and it is suggested that X-ray weakness may occur more frequently among more luminous regime. To investigate the nature of X-ray weak objects, we propose XMM-Newton observations of five optically-luminous X-ray--weak NLS1s.

Matsumoto, Chiho

2005-10-01

452

Experimental approaches for solution X-ray scattering and fiber diffraction  

SciTech Connect

X-ray scattering and diffraction from non-crystalline systems have gained renewed interest in recent years, as focus shifts from the structural chemistry information gained by high-resolution studies to the context of structural physiology at larger length scales. Such techniques permit the study of isolated macromolecules as well as highly organized macromolecular assemblies as a whole under near-physiological conditions. Time-resolved approaches, made possible by advanced synchrotron instrumentation, add a crucial dimension to many of these investigations. This article reviews experimental approaches in non-crystalline X-ray scattering and diffraction that may be used to illuminate important scientific questions such as protein/nucleic acid folding and structure-function relationships in large macromolecular assemblies.

Tsuruta, H.; Irving, T.C. (IIT); (SSRL)

2008-11-03

453

The Biomechanics of Amnion Rupture: An X-Ray Diffraction Study  

PubMed Central

Pre-term birth is the leading cause of perinatal and neonatal mortality, 40% of which are attributed to the pre-term premature rupture of amnion. Rupture of amnion is thought to be associated with a corresponding decrease in the extracellular collagen content and/or increase in collagenase activity. However, there is very little information concerning the detailed organisation of fibrillar collagen in amnion and how this might influence rupture. Here we identify a loss of lattice like arrangement in collagen organisation from areas near to the rupture site, and present a 9% increase in fibril spacing and a 50% decrease in fibrillar organisation using quantitative measurements gained by transmission electron microscopy and the novel appl