Fig. 1: The intensity of observed reflections depends on physical factors.
From: A unifying Bayesian framework for merging X-ray diffraction data
a Geometry of a conventional diffraction experiment: a crystal (shown as a hexagon) scatters an incident X-ray beam and yields a pattern of reflections (gray spots) on a detector. Three metadata of the measurements are indicated: scattering angle 2θ, crystal rotation angle, and polar angle, ϕ. b-d depict the dependence of the observed intensity distributions on these metadata for a hen egg-white lysozyme dataset. The 2-dimensional histograms show the number of counts in each of bins on a logarithmic scale. White dashed lines indicate the median intensity in each x-axis bin. Reflections with I/σI < = 0 were discarded from this analysis. b Diffraction intensities decrease with increasing scattering angle, or resolution. c Diffraction intensities vary with crystal rotation angle, a proxy for cumulative radiation dose and variations in diffracting volume. d Diffraction intensities depend on polar angle due to polarization of the X-ray source and absorption effects.
