Diffractometer-Control Software For Bragg-Rod Measurements

We present Generalized Diffractometer Control (GDC), a diffractometer-control software package developed specifically for high-precision measurements of Bragg rods; we discuss its features and analyze its performance in data collection. GDC, implemented at several APS beamlines, controls a six-circle diffractometer in either Eulerian or kappa geometry, yet does not assume a mechanically ideal diffractometer; instead, the measured directions of the diffractometer axes (and the direction of the incident beam) are input parameters. The Labview-based program features a graphical interface, making it straightforward to find all the commands and operations. Other features include optimized scans along Bragg rods, straightforward background subtraction, and extensive sets of pseudomotors.