On distortions of the shape of Bragg peaks in a neutron powder diffractometer

Abstract

We previously developed the mathematically correct method for describing the shape of Bragg peaks in powder neutron diffractometers taking into account the spatial effects. However, the used approximations are valid only in the case of a relatively small height of the detector window and sample. To increase the signal intensity, the efforts are often made for increasing these parameters, which results in specific distortions of peak shapes. The proposed method taking into account these distortions supplements the results of our previous works extending their capabilities. The analytical character of description combined with high universality of the obtained formulas applicable for instruments of different types allow us to search for the most optimal experimental conditions, to draw conclusions about the influence of different instrumental parameters, and to apply corrections to experimental results.