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Jan Ilavsky edited this page Dec 30, 2021 · 9 revisions

Welcome to wiki for Irena, Nika, and Indra packages by Jan Ilavsky, APS, ANL!

About author: https://usaxs.xray.aps.anl.gov/staff/jan-ilavsky

Introduction

Small-angle scattering : is method of measurement of large size features in sample (typically 1 nm to 25 micrometers) using X-ray, neutron or light scattering.

Wide angle scattering : aka "powder diffraction", is method of measurement of scattering from 1 nm to 0.01 nm length-scales in the sample, typically measurement of diffraction peaks from crystalline phases, but also from amorphous phases and liquids.

Igor Pro : is platform/programming environment used by all the packages. You can find details here : https://www.wavemetrics.com/index.html

Irena : is package of tools for analysis of small-angle scattering (SAXS, SANS, USAXS, USANS) data. It is mostly usable for analysis of data in materials science, chemistry, polymers, metallurgy, physics, and other systems of typically solid or liquid samples. It addresses complex systems with size distributions, hierarchical structures, diffraction peaks, etc. For systems which exhibit more "form factor" scattering use any of many other data analysis packages as this is not best use of Irena capabilities. Irena also contains simple X-ray and neutron reflectivity tool, for more complex systems use Motofit http://motofit.sourceforge.net/wiki/index.php/Main_Page. Irena is typically not used for analysis of data from most bio-SAXS experiments, there you most likely need program ATSAS https://www.embl-hamburg.de/biosaxs/software.html.

Nika : is data reduction package for small-angle (SAXS), grazing incidence small-angle (GISAXS), and wide angle (WAXS, powder diffraction) instruments. It performs image corrections, calibration, masking,... and reduction of 2D images to 1D Intensity vs scattering vector (d-spacing, angle...) lineouts. It is suitable to prepare data for Irena or any other data analysis program, which used 1D lineouts. Similar programs are Fit2D, Datasqueeze, and GSAS-II (pyGSAS, https://subversion.xray.aps.anl.gov/trac/pyGSAS). For various reasons I suggest to use GSAS-II if you do not want to use Nika.

Indra : is data reduction package for Bonse-Hart USAXS instrument, main part of the USAXS/SAXS/WAXS facility https://usaxs.xray.aps.anl.gov/ at the beamline 9ID of the Advanced Photon Source https://www.aps.anl.gov/, Argonne National Laboratory, IL, USA. This unique instrument measures, in one ~3 minutes scan, scatterer sizes in the sample from about 0.7 A to around 2 microns. Thanks to this uniquely large measured size range this instrument has currently no real competition in the world, at least as far as I know.

Competition : Number of competing packages can be found in various listings, e.g., http://gisaxs.com/index.php/Software, http://smallangle.org/content/software

Have questions? Use our Gitter forum: https://gitter.im/SAXS_IgorCode/Lobby#