SXNS13: Surface X-ray and Neutron Scattering Conference in Hamburg

The 13th Surface X-ray and Neutron Scattering Conference took place from July 7–11, 2014, on the DESY site in Hamburg, Germany. The meeting was attended by about 140 participants from all over the world.     

表面特征与软X射线掠入射光学散射

介绍了短波段掠入射表面散射线性模型,并且根据这个理论,分析计算了不同的表面特征对软X射线掠入射光学散射特性的影响。实验发现:随着粗糙度的增加、自相关长度的减小,软X射线掠入射光学散射越来越严重。     

2011 U.S. National School on Neutron and X-ray Scattering

The 13^th annual U.S. National School on Neutron and X-ray Scattering was held June 11-25, 2011, at both Oak Ridge and Argonne National Laboratories. This school brought together 65 early career graduate students from 56 different universities in the United States and provided them with a broad introduction to the properties and techniques available at the major large-scale neutron and synchrotron X-ray facilities. This school is focused primarily on techniques relevant to the physical sciences, but also touches on cross-disciplinary bio-related scattering measurements. During the school, the students received lectures by more than 30 researchers from academia, industry, and national laboratories and participated in a number of short demonstration experiments at Argonne's Advanced Photon Source (APS) and Oak Ridge's Spallation Neutron Source (SNS) and High Flux Isotope Reactor (HFIR) facilities to get hands-on experience in using neutron and synchrotron sources.     

User Training at SSRL: Crystallography,X-ray Absorption Spectroscopy,Small-Angle X-ray Scattering,and X-ray Scattering Techniques

The Stanford Synchrotron Radiation Lightsource (SSRL) is a national scientific user facility at the SLAC National Accelerator Laboratory that provides high-brightness X-ray beams, innovative experimental facilities, and expert scientific support as a resource to study our world at the atomic and molecular level. Operating within this context and being closely associated with a major research university (Stanford), SSRL is strongly committed to providing unique educational experiences, and serves as a vital training ground for future generations of scientists and engineers. As part of this program, SSRL oversees a series of schools and workshops each year which deliver theoretical, experimental, and hands-on training by leading experts in their respective fields. Several of the courses held this year, attended by graduate students, postdoctoral fellows, educators and junior/senior investigators, are described in this report.     

一种检测超光滑表面粗糙度方法的初步研究

本文依据软Ｘ射线标量散射理论，给出了一种用软Ｘ射线全积分散射检测超光滑表面粗糙度ＲＭＳ值的方法，并设计和建立了测试装置，得到了新的测量结果     

Meeting Report: SSRL School on Synchrotron X-ray Scattering Techniques in Materials and Environmental Sciences: Theory and Application

Modern synchrotron-based X-ray scattering (SR-XRS) techniques offer the ability to probe nano- and atomic-scale structures, interfaces, and order/disorder relationships that govern the properties of advanced technological and environmental materials. Important materials studied at the Stanford Synchrotron Radiation Laboratory (SSRL) include thin films and interfaces, nanoparticles, amorphous materials, solutions, polymers, and bacteriogenic minerals. Good planning and a working knowledge of beam lines and techniques are required to successfully conduct SR-XRS measurements. This second annual School at SSRL on Synchrotron X-ray Scattering Techniques in Materials and Environmental Sciences, held at the Stanford Linear Accelerator Center (SLAC) on May 15–17, 2007, provided a practical users' guide to planning and conducting scattering measurements at SSRL beam lines, with an emphasis on information that cannot be found in textbooks. More than 45 researchers, mostly graduate students and postdocs, participated in this crosscutting workshop. Attendees represented a variety of fields including material sciences, applied physics, environmental sciences, and chemistry.     

Scattering contrast of X-ray radiation

It is experimentally established that, in the majority of cases, the X-ray radiation scattered on different constituent parts of a weakly absorbing object provides sufficient information on inner structure, different types of structural inhomogeneities, and morphological characteristics, such as shapes, sizes, and location of invisible defects of the object. In this study, a new method for investigation of the inner structure of noncrystalline materials is developed. The method is based on recording of the scattered X-ray radiation. It is demonstrated that the image contrast, formed by the X-ray radiation scattered on weakly absorbing objects, can be considerably higher than the absorption contrast.     

SSRL Fifth Annual School on Synchrotron X-ray Scattering Techniques in Materials and Environmental Sciences: Theory and Application

Synchrotron-based X-ray scattering (SR-XRS) techniques offer the ability to probe nano- and atomic-scale structure that dictates the properties of advanced technological and environmental materials. Important materials studied at the Stanford Synchrotron Radiation Lightsource (SSRL) include organic and inorganic thin films and interfaces, nanoparticles, monolayers, complex oxides, solutions, polymers, minerals, and poorly crystalline materials. Good planning and a working knowledge of beam lines and techniques are required to successfully conduct SR-XRS measurements. This fifth annual School at SSRL on Synchrotron X-ray Scattering Techniques in Materials and Environmental Sciences, held at the SLAC National Accelerator Laboratory on June 1–3, 2010, provided a practical users' guide to planning and conducting scattering measurements at SSRL beam lines, with an emphasis on information that cannot be found in textbooks. More than 45 researchers, mostly graduate students and postdoctoral associates, participated in this workshop. Attendees represented a variety of fields including material sciences, chemical engineering, applied physics, environmental and earth sciences, and chemistry.     

A Simple X-ray Spectrometer and PC-based Data Acquisition System for Newly Developed X-ray Source Based on Laser Compton Scattering

A simple X-ray spectrometer and a PC-Based Data Acquisition System(DAS) have been developed newly in Shanghai Institute of Applied Physics(SINAP),Chinese Academy of Sciences (CAS) for the measurement of the X-ray source generated using laser Compton scattering.The system consists of liquid nitrogen cooled high resolution Si(Li) detector,electronics and a DAQ.The Si(Li) detector was designed and made by Center of Advanced Instruments in SINAP,CAS,it allows us to measure X-rays with the energy up to 60 keV and the energy resolution(FWHM) of 184 eV at 5.9 keV.We measured the system uncertainty was 0.2 eV and time drifting of detector was 0.05% both at 5.9 keV.The DAQ was based on Object-Oriented software LabVIEW 7.1,it has data on-line analysis and original data saved functions.     

Anomalous Decrease in the Threshold of Stimulated Raman Scattering near the Surface of Liquid Nitrogen

JETP Letters - An anomalously strong (up to 13 times) reduction of the threshold of the stimulated Raman scattering of 15-ps laser pulses in liquid nitrogen has been found when moving the caustic...     

X-ray scattering: Liquid metal/vapor interfaces

Dilute aqueous solutions of alcohols with a high number of carbon atoms can be considered as self-rewetting fluids due to their properties associated to an anomalous dependency of the surface tension with temperature in some ranges of concentrations. In this paper research activities focused on numerical simulations and laboratory experiments of the behaviour of a thin layer of liquid subject to a horizontal thermal gradient. The investigated liquids include ordinary liquids and water/alcohols mixtures. Physical properties measurements, in particular surface tension and refractive index, are also presented. Flow visualization and interferometric analysis have been carried out using optical diagnostic systems.     

X-ray Resonance Exchange Scattering (XRES)

Large resonant magnetization-sensitive X-ray scattering is predicted to occur in the vicinity of the L_II, L_III, M_II-M_V absorption edges in the rare earth and actinide elements, and at the L_II, L_III edges in the transition and 4d elements. Additional longer wavelength resonances will occur in the actinides and 4d elements. These “magnetic” resonances result from electric multipole transitions, with the sensivity to the magnetization arising from exchange and spin-orbit correlations. For some transitions, the magnetic scattering will be comparable to the charge scattering.     

Scattering Theory with Finite-Gap Backgrounds: Transformation Operators and Characteristic Properties of Scattering Data

We develop direct and inverse scattering theory for Jacobi operators (doubly infinite second order difference operators) with steplike coefficients which are asymptotically close to different finite-gap quasi-periodic coefficients on different sides. We give necessary and sufficient conditions for the scattering data in the case of perturbations with finite second (or higher) moment.     

表面等离激元协助的方向性瑞利光散射研究

The origin of the Rayleigh scattering ring effect has been experimentally examined on a quantum dot/metal film system, in which CdTe quantum dots embedded in PVP are spin-coated on a thin Au film. On the basis of the angle-dependent, optical measurements under different excitation schemes (i.e., wavelength and polarization), we demonstrate that sur-face plasmon assisted directional radiation is responsible for such an effect. Moreover, an interesting phase-shift behavior is addressed.