Advanced Photon Source

An Office of Science National User Facility

QXRD – Real Time Readout, Visualization and Data Reduction for powder diffraction and SAXS

A screen shot of the main interface to QXRDThe Perkin Elmer XRD series flat panel detectors are marketed for use as medical X-ray imaging detectors but their relatively low price, large area and fast readout rate makes them attractive for use as general purpose X-ray detectors for synchrotron measurements.In this application it is necessary to integrate them into an existing experimental control setup.QXRD is software written in C++ using the Qt graphics framework; it provides an integrated real time readout, visualization and data reduction package for X-ray synchrotron experiments.

Throughout the development of QXRD, a prime concern has been to make it as accessible as possible to other users – binary installers are provided as a matter of course and the installation is very nearly entirely self contained. Very little configuration is required after installation – in most cases acquisition will ‘just work’ immediately after installation.

The visualization and data reduction facilities provided are aimed primarily at powder diffraction and/or SAXS measurements. The performance is such that visualization and data reduction can almost always be performed at the maximum data rate of the detector.

Recent work has focused on implementing corrections for detector image plane distortions, which have been found to have a small but measurable effect on powder diffraction measurements. By fitting diffracted ring positions to images measured from calibrant samples and comparing measured vs calculated diffraction angles, one can create a Delaunay triangulation of reference positions which may be used to correct the angle scale of an integrated powder diffraction image.


Distribution & Impact

Detector distortion calibrations for a single detector, measured at a number of different sample to detector distances.QXRD is released under a GNU license.Binary installers for Windows and Mac OS are provided, as well as .rpm packages for Fedora Linux are available from the sourceforge page at as well as source code from the git repository.


Funding Source

This project has been produced using operational funding from the APS, contract DE-AC02-06CH11357.