Create Ikeda Carpenter Parameters

Example of how a parameter can be determined on a beamline

The steps involved in creating instrument specific parameters for the Ikeda-Carpenter-Pseudo-Voigt peak shape function are on ISIS/GEM approximately as follows:

  • Run calibration samples: NIST standard Silicon and Y2O3.

  • Combined rietveld refined of these two standards in either Fullprof or GSAS

  • All structural parameters are fixed but not the Ikeda Carpenter parameters and background parameters (and zero shifts). On GEM, the Ikeda-Carpenter parameters are the same for all banks but the Pseudo-Voigt sigma and gamma parameters which are refined differently for the different banks.

  • Finally the information from this refinement is copied and pasted from output files to generate either a Fullprof or GSAS instrument parameter files.

Category: Techniques