Everything SAXS: small-angle scattering pattern collection and correction

Irena, a tool suite for analysis of both X-ray and neutron small-angle scattering (SAS) data within the commercialIgor Proapplication, brings together a comprehensive suite of tools useful for investigations in materials science, physics, chemistry, polymer science and other fields. In addition to Guinier and Porod fits, the suite combines a variety of advanced SAS data evaluation tools for the modeling of size distribution in the dilute limit using maximum entropy and other methods, dilute limit small-angle scattering from multiple non-interacting populations of scatterers, the pair-distance distribution function, a unified fit, the Debye–Bueche model, the reflectivity (X-ray and neutron) using Parratt's formalism, and small-angle diffraction. There are also a number of support tools, such as a data import/export tool supporting a broad sampling of common data formats, a data modification tool, a presentation-quality graphics tool optimized for small-angle scattering data, and a neutron and X-ray scattering contrast calculator. These tools are brought together into one suite with consistent interfaces and functionality. The suite allows robust automated note recording and saving of parameters during export.

Nikais anIgor Pro-based package for correction, calibration and reduction of two-dimensional area-detector data into one-dimensional data (`lineouts'). It is free (although the user needs a paid license forIgor Pro), open source and highly flexible. While typically used for small-angle X-ray scattering (SAXS) data, it can also be used for grazing-incidence SAXS data, wide-angle diffraction data and even small-angle neutron scattering data. It has been widely available to the user community since about 2005, and it is currently used at the SAXS instruments of selected large-scale facilities as their main data reduction package. It is, however, also suitable for desktop instruments when the manufacturer's software is not available or appropriate. Since it is distributed as source code, it can be scrutinized, verified and modified by users to suit their needs.