A customizable software for fast reduction and analysis of large X-ray scattering data sets: applications of the new DPDAK package to small-angle X-ray scattering and grazing-incidence small-angle X-ray scattering.

Gunthard Benecke,Rebecca Hoerth,Ezzeldin Metwalli,Wolfgang Wagermaier,Stephan V Roth,Oskar Paris,Manfred Burghammer,Stephan Förster,Peter Fratzl,Peter Müller-Buschbaum,Martin Trebbin,Ivo Zizak,Chenghao Li,Matthias Schwartzkopf,Gero Flucke

doi:10.1107/s1600576714019773

Abstract

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 of DPDAK for 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 of DPDAK and the possibilities and limitations are discussed.

Highlights

High-brilliance synchrotron radiation sources allow today’s use of X-ray scattering methods with a spatial resolution in the range of micro- and even nanometres (Riekel, 2000; Paris, 2008; Narayanan, 2009)
First we show two examples where the nanostructure of biological bone samples is determined by scanning SAXS and WAXS experiments at the Spot beamline at BESSY II (HZB, Berlin, Germany) and at the microfocus beamline ID 13 at ESRF (Grenoble, France)
This is followed by two experiments performed at the MiNaXS/P03 beamline at PETRA III (DESY, Hamburg, Germany) which highlight the online analysis of grazing-incidence smallangle X-ray scattering (GISAXS) experiments to track sputtering of gold on silicon and polymer substrates

Summary

Introduction

High-brilliance synchrotron radiation sources allow today’s use of X-ray scattering methods with a spatial resolution in the range of micro- and even nanometres (Riekel, 2000; Paris, 2008; Narayanan, 2009). Data reduction and simple analyses, such as the extraction of invariants (Porod, 1951) of the SAXS or SANS curve, are needed to pre-screen the data and have to be carried out before in-depth analyses, often with large amounts of data and in an online fashion directly during the data collection to allow for potential modifications of the experimental strategy This leads to the following four essential key features for a fast onor offline data reduction and analysis software: (i) an easy adaptation to specific needs; (ii) an online mode enabling a pre-analysis of data in parallel to measurements, with automatic handling of new data as well as the ability to deal with high data rates; (iii) an open-source philosophy, which is essential to verify and extend the functionality and to allow the software to be maintained by a larger group; and (iv) support of Windows and Linux operating systems. We demonstrate how DPDAK can be used for online analysis of scanning SAXS/WAXS experiments and in situ GISAXS sputter deposition experiments

Specifications and features

Workflow and framework structure

Results and discussion of application examples

Conclusions and outlook