Technical University of Denmark

X-ray free electron lasers require 2D area detectors with large dynamic range for detection of hard x-rays with fast readout rates. Extracting the desired information from such detectors has been challenging due to unpredicted fluctuations in the measured images. We present a methodology for robustly identifying, separating and correcting fluctuations on area detectors based on the XFEL beam characteristics. With techniques such as time-resolved x-ray diffuse scattering, small differences in signal intensity are the starting point for analysis. Fluctuations in the total detected signal carry on to the differences under investigation, obfuscating the signal. To correct such artefacts, Singular value decomposition (SVD) can be used to map out the observed detector fluctuations and assist in assigning some of them to variations in physical parameters such as x-ray energy and x-ray intensity. Correcting the detector images improve the output of the following analysis and allow for extraction of weaker signals as well as analysis of the full 2D images.