Calibration and error analysis of an arc detector for wide-angle X-ray scattering (WAXS)

In wide-angle X-ray scattering (WAXS) experiments, the use of a one-dimensional arc detector can effectively expand the angle range of collected diffraction or scattering signals. In practice, the relative positions between the centers of arc detector, sample and beam spot may overlap or misalign. Therefore, it is necessary to calibrate the instrument parameters and detection angle of the arc detector. The calibration is routinely performed by standard samples. In this contribution, the equations for angle calibration and error evaluation are constructed based on three standard diffraction peaks, and the corresponding simulation and experiment are performed to verify the feasibility of the calibration. The results indicate that the larger the coverage and the more uniform the dispersion of the three standard diffraction peaks distributed on the detector, the smaller the calibration error.