X-ray diffraction-based defective pixel correction method using an active pixel array sensor

摘要

A method for correcting erroneous intensity measurements caused by defective pixels of the detector for a single-crystal X-ray diffraction system uses collected diffraction images and a defective pixel list to modify three-dimensional reflection profiles by replacing profile elements affected by the defective pixels with corresponding profile elements from a model profile. Reflection positions on the detector are predicted using an orientation matrix for the crystal and a three-dimensional observed profile is constructed for each reflection. A model profile is constructed using normalized profile data from multiple reflection profiles. The observed profiles are compared with the defective pixel list to determine which profile elements are affected by defective pixels, and those elements are replaced by corresponding elements from the model profile. If the replaced elements represent more than a predetermined percentage of the overall reflection intensity, the data for that reflection is omitted from an overall dataset for the crystal.

主权项

1. A method of correcting erroneous intensity measurements caused by defective pixels of the detector of a single-crystal X-ray diffraction system during the collection of diffraction images from a plurality of different scan angles for a crystal mounted in the system, the method comprising the steps of:
a) predicting reflection positions on the detector from the diffraction images using an orientation matrix established for the crystal; b) constructing a three-dimensional observed profile for each reflection, said observed profile being indicative of pixel intensity relative to scan angle for detector pixels falling within a predicted reflection position as determined in step (a); c) constructing a model profile as an average of the normalized profile data from a plurality of observed profiles; d) providing a defective pixel list for the system indicative of the location of defective pixels in the detector; and e) for each reflection under examination, comparing the defective pixel list with the observed profile for that reflection to determine components of that observed profile that are affected by a defective pixel, and replacing said components with corresponding components from the model profile.