Uncertainty evaluation of the NRC imaging diffractometer

A model equation is developed for a diffractometer operating under the Littrow condition. The effects of grating orientation, grating position, source and detector position and source collimation are included. The model is validated against experimental measurements using the NRC imaging diffractometer. Errors due to the effects of coherence and grating position were found to be important for the small area gratings used in these experiments. An uncertainty budget for the NRC imaging diffractometer is developed and reproducibility measurements are presented.