2006 XSD Scientific Software User Survey.

In preparation for the 2006 XSD Scientific Software workshop, our committee sent a survey on June 16 to 100 users in the APS user community. This report contains the survey and the responses we received. The responses are presented in the order received

2006 XSD Scientific Software Workshop report.

In May of 2006, a committee was formed to assess the fundamental needs and opportunities in scientific software for x-ray data reduction, analysis, modeling, and simulation. This committee held a series of discussions throughout the summer, conducted a poll of the members of the x-ray community, and held a workshop. This report details the findings and recommendations of the committee. Each experiment performed at the APS requires three crucial ingredients: the powerful x-ray source, an optimized instrument to perform measurements, and computer software to acquire, visualize, and analyze the experimental observations. While the APS has invested significant resources in the accelerator, investment in other areas such as scientific software for data analysis and visualization has lagged behind. This has led to the adoption of a wide variety of software with variable levels of usability. In order to maximize the scientific output of the APS, it is essential to support the broad development of real-time analysis and data visualization software. As scientists attack problems of increasing sophistication and deal with larger and more complex data sets, software is playing an ever more important role. Furthermore, our need for excellent and flexible scientific software can only be expected to increase, as the upgrade of the APS facility and the implementation of advanced detectors create a host of new measurement capabilities. New software analysis tools must be developed to take full advantage of these capabilities. It is critical that the APS take the lead in software development and the implementation of theory to software to ensure the continued success of this facility. The topics described in this report are relevant to the APS today and critical for the APS upgrade plan. Implementing these recommendations will have a positive impact on the scientific productivity of the APS today and will be even more critical in the future

Patterning graphene nanoribbons using copper oxide nanowires

Site-controlled InP/GaInP quantum dots emitting single photons in the red spectral range Appl. Phys. Lett. 100, 091109 (2012) Micromagnet structures for magnetic positioning and alignment J. Appl. Phys. 111, 07B312 (2012) Influence of low anisotropy inclusions on magnetization reversal in bit-patterned arrays J. Appl. Phys. 111, 033924 (2012) Additional information on J. Appl. Phys. The formation of Al nanocrystals from an amorphous Al 92 Sm 8 alloy involves kinetic phenomena with very different characteristic length and timescales, including initial nucleation and later growth and coarsening. Insight into these processes can be derived from the evolution of the sizes of nanocrystals as a function of time. Synchrotron small angle x-ray scattering (SAXS) experiments provide information about the evolution of the nanocrystal size distribution, particularly at times after nucleation has reached saturation. Accurately interpreting the distribution of intensity measured using SAXS requires a nanoparticle model consisting of nanocrystalline core of pure Al surrounded by a shell enriched in Sm. With this approach, statistical parameters derived from SAXS are independent of detailed assumptions regarding the distribution of Sm around the nanocrystals and allow the maximum radius of nanocrystals within the distribution to be determined unambiguously. Sizes determined independently using transmission electron microcopy are in excellent agreement with the SAXS results. The maximum radius obtained from SAXS is proportional to the cube root of time at large sizes and long times, consistent with a coarsening model. The diffusivity of Al within the Al-Sm alloy is obtained from a quantitative analysis of the coarsening process. Further analysis with this diffusivity and a particle growth model provides a satisfactory account for the particle size evolution at early times before the kinetic transition to coarsening. V C 2012 American Institute of Physics. [http://d

A gradient method for anomalous small-angle x-ray scattering

A new method of general applicability for analyzing data from anomalous dispersion small-angle X-ray scattering (ASAXS) measurements is described. ASAXS is used as a contrast variation method to label the scattering from a single element in a complex material containing several types of scatterers. The contrast variation is achieved through the anomalous dispersion of X-rays. Thus only one sample is required for a complete analysis. To label a scatterer by ASAXS, the atomic scattering factor of an element in the sample is varied by the selection of photon energies near the absorption edge of the element. Careful selection of the photon energies allows the contrast of only the labeled scatterer to change. Data from several small-angle scattering measurements, each conducted at a fixed energy, are combined in a single analysis. The gradient method, used as an extension to a standard SAXS data analysis method, is demonstrated by isolating the volume fraction size distribution of Cr{sub 23}C{sub 6} in 9Cr-1 MoVNb steel

T.-C.: Determination of Phonon Dispersion from X-ray Transmission Scattering: the Example of Silicon.

A beam of monochromatic synchrotron x-ray incident on a silicon wafer creates a rich intensity pattern behind the wafer that reflects the cross section of scattering by thermally populated phonons. A least-squares fit of the patterns based on a lattice dynamics calculation yields the phonon dispersion relations over the entire reciprocal space. This simple and efficient method is suitable for phonon studies in essentially all materials, and complements the traditional neutron scattering technique. PACS numbers: 78.70.Ck, 63.20.Dj Phonons are the fundamental quanta of lattice vibration in a solid. They play a critical role in phenomena such as superconductivity and many types of phase transitions, and are the basis for the acoustic, thermal, elastic, and infrared properties of solids Although intensity distribution of x-ray scattering by thermally populated phonons has been long recognized as a possible measure of phonon properties Our experiment was performed at the undulator beam line of Sector 33 (University, Industry, and National Laboratory Collaborative Access Team) at the Advanced Photon Source. A transmission Laue geometry was employed, in which a 28 keV beam was sent at normal incidence through commercial Si wafers with a thickness of 0.5 mm. An image plate positioned behind the sample was used to record the images with an exposure time of ϳ10 s each. The incident beam was polarized in the horizontal direction. Data were taken with the sample in air, in a helium atmosphere, or in vacuum with similar results. The data shown below were taken with the sample in air. Figures 1(a) and 1(b) are experimental pictures of Si Each point in the picture corresponds to a planar projection of a unique momentum transfer q on the Ewald sphere. Because each unit cell of Si contains two atoms, there can 0031-9007͞99͞83(16)͞3317(3)$15.0

Radiation embrittlement studies using anomalous small-angle x-ray scattering

Anomalous small angle x-ray scattering (ASAXS) was performed on an Fe-O.9 wt.% Cu-1.0 wt.% Mn alloy subjected to annealing or electron irradiation. ASAXS takes advantage of natural variations in the atomic scattering factor which exist at energies very near an element's x-ray absorption edge. By performing systematic SAXS experiments at energies near these absorption edges of the constituent alloy elements it is possible to vary the contrast of scattering centers containing the elements and in doing so quantify scatterer composition. The results of such an analysis for the samples in this work indicate the presence of Cu-rich, Cu{sub 85}Mn{sub 15} precipitates in the alloy. By applying the maximum entropy technique to the scattering data, it was possible to extract size distributions of scattering centers fog the different treatments. The results demonstrate the ability to detect and characterize small (11 {angstrom} radius) scatterers at quite low irradiation damage levels (5x10{sup {minus} 4} displacements per atom)

D-108 In Situ Studies of Nano-Particle Growth in Flames—Invited

ISSN:0885-715