APS USAXS/SAXS/WAXS facility

Ultra-Small-Angle X-ray Scattering Facility

Irena

Tools for analysis of small-angle scattering data

Irena is set of tools for data manipulations and analysis for small-angle scattering (SAXS, SANS, USAXS, USANS) and powder diffraction (XRD, WAXS) data. It is mostly used 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. Irena also contains simple X-ray and neutron reflectivity tool, for more complex systems use Motofit. Irena also provides set of tools for bioSAXS users and can utilize its own tools and gnom from ATSAS package to generate PDDF. More bioSAXS tool may be added. 

Irena requires commercial package Igor Pro 9.0x or 10.x from Wavemetrics, Inc.  

NOTE: pyIrena (or here) is Python package developed for macOS, Windows, and Linux. pyIrena is conversion of Irena tools using Anthropic Claude and verified against Irena. More details here.

Irena (Igor Pro):

  • Unified fit
  • Modeling   - Direct modeling of SAS from up to 10 populations on up to 10 data sets at once. Selection of form factors and structure factors, Unified fit, Mass or Surface Fractal, and Diffraction peaks.
  • Size distribution - using Max. Ent., TNNLS and Regularization
  • Guinier-Porod model
  • Fractal model (combination of mass and surface fractals)
  • X-ray and Neutron reflectivity using Parrat's recursive method
  • Small-angle diffraction tool (up to 6 diffraction peaks)
  • Powder diffraction peak fitting tool (WAXS)
  • System specific models
    • Debye-Bueche,
    • Ciccariello-Benedetti,
    • Treubner-Streus models
    • Hermans, Modified Hermans, and Unified Born Green (correlated lamellae systems)
  • Pair distance distribution function (PDDF, P(r))
  • Hermans Orientation Parameter. See e.g., Macromolecules 2004, 37, 5327-5336, formula 1.
  • Visualization tools    
    • Mass Fractal Aggregate - 3D Monte Carlo shape reconstruction
  • bioSAXS tools
    • Basic/simple fits (Guinier, Porod,...)
    • PDDF/Molecular weight using GNOM and other tools. 

    Support tools

  • Data import - imports data from ASCII & XML (CanSAS XML) files
  • Data export - exports data to ASCII files
  • Data plotting tools - 2D, 3D, can create movies of plots.
  • Data manipulation tools
    • Merging of two overlapping data sets (SAXS curves from different distances etc.).
    • Subtract, scale, multiply, etc. - change data as needed.
  • Scattering contrast calculator, including anomalous effects using Croman-Liberman code
  • Desmearing using Lake method
  • Data "mining" tool, Metadata browser, etc.
  • Scripting tool - scripts Unified fit, Modeling II, Plotting tool, and Size distribution to run automatically on multiple data sets
  • bioSAXS tools
    • Import simple ASCII
    • Average multiple measurements
    • Subtract buffer and scale
    • Concentration extrapolation tool

For more detailed description, please see here: http://saxs-igorcodedocs.readthedocs.io/en/stable/Irena/Introduction.html

On-line manual : We now have on-line manual, you can open it in you web browser and read it here: http://saxs-igorcodedocs.readthedocs.io/

Wiki : There is now wiki for Irena and Nika packages on our Github depository. Check it up - questions of general importance may be answered there, if someone already asked them.

Mailing group for Irena users: If you want to be informed about Irena updates and possibly have place to inquire about SAXS/SANS analysis problems, visit the page: http://www.aps.anl.gov/mailman/listinfo/irena_users where you can join this group.

Workshops on using Irena & Nika packages... since 2012 we organize at the APS 1-3 sessions per year workshops on use of Irena and Nika packages. Next workshop is being considered. 

Current Irena version :  2.74 released 6/27/2025, 
                              June2025 release. 

Current Irena beta version : 2.75 released 1/6/2026,
                                    January2026Beta release. 

How to install:

Method Download link Instructions
Igor 9.x
Igor 8.04		  

Igor Pro 8.04 and Igor Pro 9.x
Installer
(preferred)

GithubInstaller

older GithubInstaller

 Check Youtube channel for instructions.
Uses Github to distribute Irena, Nika, and Indra.
Most likely what you want!
Clone & link Github depository Clone the Github depository to your computer and link folders from your clone to proper Igor locations. If you need help, let me know.
NOTE: Github depository "master" version should be considered development version and while I try to submit to Github only working versions, the code is "beta" version only...
Test data for
Youtube channel		 Github depository

Size Distribution tool test data

and other tools, browse the depository 
User form factors for Modeling in Irena Github depository Github location with available User Form Factors for use in Modeling package. Download the ones you need.
If you develop one and can share, please, send it to author to be included here... 
     
    Older versions, no development anymore:
Igor 7.08    Upgrade Igor Pro to higher version. Igor 7.08 is obsolete by now.  
Installer GithubInstaller Update to Igor Pro 7.08
Use Installer version 1.10 and install
version 2.69 (February2020 release).
Check Youtube channel for instructions
Irena higher versions than 2.69 are not tested in Igor 7.08 and may not work.  

Obtaining help:

Disclaimer:

This set of macros is currently being developed for use on any SAS data. Their use by anyone for open science is free of charge. If you want to use them for proprietary work, please contact author for permission. There are no warrantees with respect to functionality of these macros, please, verify all results by independent methods.