scholarly journals Unwarping GISAXS data

IUCrJ ◽  
2018 ◽  
Vol 5 (6) ◽  
pp. 737-752 ◽  
Author(s):  
Jiliang Liu ◽  
Kevin G. Yager
Keyword(s):  
Born Approximation ◽  
Grazing Incidence ◽  
Initial Guess ◽  
Reciprocal Space ◽  
Scattering Data ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission And Reflection

Grazing-incidence small-angle X-ray scattering (GISAXS) is a powerful technique for measuring the nanostructure of coatings and thin films. However, GISAXS data are plagued by distortions that complicate data analysis. The detector image is a warped representation of reciprocal space because of refraction, and overlapping scattering patterns appear because of reflection. A method is presented to unwarp GISAXS data, recovering an estimate of the true undistorted scattering pattern. The method consists of first generating a guess for the structure of the reciprocal-space scattering by solving for a mutually consistent prediction from the transmission and reflection sub-components. This initial guess is then iteratively refined by fitting experimental GISAXS images at multiple incident angles, using the distorted-wave Born approximation (DWBA) to convert between reciprocal space and detector space. This method converges to a high-quality reconstruction for the undistorted scattering, as validated by comparing with grazing-transmission scattering data. This new method for unwarping GISAXS images will broaden the applicability of grazing-incidence techniques, allowing experimenters to inspect undistorted visualizations of their data and allowing a broader range of analysis methods to be applied to GI data.

Debye–Scherrer rings from block copolymer films with powder-like order

2011 ◽  
Vol 44 (2) ◽  
pp. 370-379 ◽  
Author(s):  
Peter Busch ◽  
Markus Rauscher ◽  
Jean-François Moulin ◽  
Peter Müller-Buschbaum
Keyword(s):  
Small Angle ◽  
Critical Angle ◽  
Grazing Incidence ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
X Ray ◽  
Copolymer Films ◽  
X Ray Scattering ◽  
Ring Shape ◽  
Neutron Time

The powder-like orientation of lamellar domains in thin films of the diblock copolymer polystyrene-block-poly(methyl methacrylate) is investigated using grazing-incidence small-angle X-ray scattering (GISAXS) and grazing-incidence small-angle neutron scattering (GISANS). Conventional monochromatic GISANS and GISAXS measurements are compared with neutron time-of-flight GISANS. For angles of incidence and exit larger than the critical angle of total external reflection of the polymer, Debye–Scherrer rings are observed. The position of the Debye–Scherrer rings is described quantitatively based on a reduced version of the distorted-wave Born approximation. A strong distortion of the ring shape is caused by refraction and reflections from the film interfaces. Close to the critical angle, the ring shape collapses into a banana shape.

Grazing-incidence small-angle X-ray scattering from thin polymer films with lamellar structures – the scattering cross section in the distorted-wave Born approximation

2006 ◽  
Vol 39 (3) ◽  
pp. 433-442 ◽  
Author(s):  
P. Busch ◽  
M. Rauscher ◽  
D.-M. Smilgies ◽  
D. Posselt ◽  
C. M. Papadakis
Keyword(s):  
Thin Films ◽  
Polymer Films ◽  
Small Angle ◽  
Born Approximation ◽  
Grazing Incidence ◽  
Thin Polymer Films ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
X Ray ◽  
Thin Polymer

Grazing-incidence small-angle X-ray or neutron scattering of thin polymer films reveals information about the ordering and preferential orientations of the phase-separated microdomains within the films. The grazing-incidence geometry enhances the surface sensitivity; however, the scattering has to be treated within the framework of the distorted-wave Born approximation. In this work, the case of thin films with lamellar mesostructure is studied, where the orientation of the lamellae is either perpendicular or parallel to the film interfaces. For perpendicular lamellae, Bragg rods are found, which are extended along the film normal, whereas for parallel lamellae, peaks along the film normal appear. The positions of the maxima present in the latter case are explained by accounting for refraction at the film surface and reflection at the film–substrate interface. The results are relevant for thin films of lamellar diblock copolymers.

FitGISAXS: software package for modelling and analysis of GISAXS data using IGOR Pro

2010 ◽  
Vol 43 (4) ◽  
pp. 929-936 ◽  
Author(s):  
David Babonneau
Keyword(s):  
Software Package ◽  
Form Factors ◽  
Grazing Incidence ◽  
Three Dimensions ◽  
Scattering Data ◽  
Stratified Medium ◽  
X Ray ◽  
X Ray Scattering ◽  
Structure Factors ◽  
Scripting Language

A software package for performing modelling and analysis of GISAXS (grazing-incidence small-angle X-ray scattering) data within the distorted-wave Born approximation has been developed using the IGOR Pro scripting language (http://www.wavemetrics.com). The tool suite uses a slab-model approach with the Abélès matrix method to calculate X-ray reflectivity curves, electric field intensity distributions and GISAXS intensities from supported or buried scatterers arranged in two or three dimensions in a stratified medium. Models are included to calculate the scattered intensity for monodisperse, polydisperse and interacting particles with various size distributions, form factors and structure factors. The source code for the entire package is freely available, allowing anyone to develop additional tools.

scholarly journals Nebula: reconstruction and visualization of scattering data in reciprocal space

2015 ◽  
Vol 48 (2) ◽  
pp. 604-607
Author(s):  
Andreas Reiten ◽  
Dmitry Chernyshov ◽  
Ragnvald H. Mathiesen
Keyword(s):  
Three Dimensional ◽  
Reciprocal Space ◽  
Scattering Data ◽  
Data Sets ◽  
Real Time Processing ◽  
Time Processing ◽  
X Ray ◽  
X Ray Scattering ◽  
Data Throughput ◽  
Space Data

Two-dimensional solid-state X-ray detectors can now operate at considerable data throughput rates that allow full three-dimensional sampling of scattering data from extended volumes of reciprocal space within second to minute timescales. For such experiments, simultaneous analysis and visualization allows for remeasurements and a more dynamic measurement strategy. A new software,Nebula, is presented. It efficiently reconstructs X-ray scattering data, generates three-dimensional reciprocal space data sets that can be visualized interactively, and aims to enable real-time processing in high-throughput measurements by employing parallel computing on commodity hardware.

scholarly journals A customizable software for fast reduction and analysis of large X-ray scattering data sets: applications of the newDPDAKpackage to small-angle X-ray scattering and grazing-incidence small-angle X-ray scattering

2014 ◽  
Vol 47 (5) ◽  
pp. 1797-1803 ◽  
Author(s):  
Gunthard Benecke ◽  
Wolfgang Wagermaier ◽  
Chenghao Li ◽  
Matthias Schwartzkopf ◽  
Gero Flucke ◽  
...  
Keyword(s):  
Small Angle ◽  
Data Reduction ◽  
Grazing Incidence ◽  
Scattering Data ◽  
Limiting Factor ◽  
Online Data ◽  
Saxs Data ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

X-ray scattering experiments at synchrotron sources are characterized by large and constantly increasing amounts of data. The great number of files generated during a synchrotron experiment is often a limiting factor in the analysis of the data, since appropriate software is rarely available to perform fast and tailored data processing. Furthermore, it is often necessary to perform online data reduction and analysis during the experiment in order to interactively optimize experimental design. This article presents an open-source software package developed to process large amounts of data from synchrotron scattering experiments. These data reduction processes involve calibration and correction of raw data, one- or two-dimensional integration, as well as fitting and further analysis of the data, including the extraction of certain parameters. The software,DPDAK(directly programmable data analysis kit), is based on a plug-in structure and allows individual extension in accordance with the requirements of the user. The article demonstrates the use ofDPDAKfor on- and offline analysis of scanning small-angle X-ray scattering (SAXS) data on biological samples and microfluidic systems, as well as for a comprehensive analysis of grazing-incidence SAXS data. In addition to a comparison with existing software packages, the structure ofDPDAKand the possibilities and limitations are discussed.

Grazing-incidence transmission X-ray scattering: surface scattering in the Born approximation

2013 ◽  
Vol 46 (1) ◽  
pp. 165-172 ◽  
Author(s):  
Xinhui Lu ◽  
Kevin G. Yager ◽  
Danvers Johnston ◽  
Charles T. Black ◽  
Benjamin M. Ocko
Keyword(s):  
Born Approximation ◽  
Three Dimensional ◽  
Grazing Incidence ◽  
Real Space ◽  
X Ray ◽  
Electron Microscopies ◽  
Beam Geometry ◽  
X Ray Scattering ◽  
Complementary Techniques ◽  
Ray Scattering

Determination of the three-dimensional order in thin nanostructured films remains challenging. Real-space imaging methods, including electron microscopies and scanning-probe methods, have difficulty reconstructing the depth of a film and suffer from limited statistical sampling. X-ray and neutron scattering have emerged as powerful complementary techniques but have substantial data collection and analysis challenges. This article describes a new method, grazing-incidence transmission small-angle X-ray scattering, which allows for fast scattering measurements that are not burdened by the refraction and reflection effects that have to date plagued grazing-incidence X-ray scattering. In particular, by arranging a sample/beam geometry wherein the scattering exits through the edge of the substrate, it is possible to record scattering images that are well described by straightforward (Born approximation) scattering models.

scholarly journals The Diffraction Pattern Calculator(DPC) toolkit: a user-friendly approach to unit-cell lattice parameter identification of two-dimensional grazing-incidence wide-angle X-ray scattering data

2014 ◽  
Vol 47 (6) ◽  
pp. 2090-2099 ◽  
Author(s):  
Anna K. Hailey ◽  
Anna M. Hiszpanski ◽  
Detlef-M. Smilgies ◽  
Yueh-Lin Loo
Keyword(s):  
Crystal Structure ◽  
Grazing Incidence ◽  
Unit Cell ◽  
Lattice Parameters ◽  
Scattering Data ◽  
Wide Angle ◽  
Two Dimensional ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

TheDPCtoolkit is a simple-to-use computational tool that helps users identify the unit-cell lattice parameters of a crystal structure that are consistent with a set of two-dimensional grazing-incidence wide-angle X-ray scattering data. The input data requirements are minimal and easy to assemble from data sets collected with any position-sensitive detector, and the user is required to make as few initial assumptions about the crystal structure as possible. By selecting manual or automatic modes of operation, the user can either visually match the positions of the experimental and calculated reflections by individually tuning the unit-cell parameters or have the program perform this process for them. Examples that demonstrate the utility of this program include determining the lattice parameters of a polymorph of a fluorinated contorted hexabenzocoronene in a blind test and refining the lattice parameters of the thin-film phase of 5,11-bis(triethylsilylethynyl)anthradithiophene with the unit-cell dimensions of its bulk crystal structure being the initial inputs.

Interface Roughness Determined by Diffuse Scattering and by Reflectivity of Hard X-Rays

1992 ◽  
Vol 280 ◽  
Author(s):  
B. Lengeler ◽  
M. Hüppauff
Keyword(s):  
Born Approximation ◽  
Diffuse Scattering ◽  
Interface Roughness ◽  
X Rays ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
X Ray ◽  
Non Destructive

ABSTRACTX-ray reflectivity and diffuse scattering are powerful techniques for the non-destructive determination of the vertical and lateral roughness of external and internal interfaces. The influence of roughness on the reflected and transmitted amplitudes is treated in terms of a model first described by Névot and Croce. The diffuse scattering is described by an improved distorted wave Born approximation. A few examples will demonstrate the possibilities of the techniques.

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