In situ X-ray area detector gain correction at an operating photon energy

TL;DR

This paper introduces a rapid method for calibrating x-ray area detector gain using scattering measurements, enabling frequent recalibration without flat field measurements, which improves detector accuracy over time.

Contribution

A novel approach to calculate detector gain maps quickly from scattering data, eliminating the need for flat field measurements at specific photon energies.

Findings

Gain maps can be obtained rapidly from scattering measurements.

Detector gain drifts over weeks or high flux exposure, necessitating frequent recalibration.

The method is applicable to detectors like Pilatus 2M CdTe and Varex XRD 4343CT.

Abstract

Gain calibration of x-ray area detectors is a challenge due to the inability to generate an x-ray flat field at the selected photon energy that the beamline operates at, which has a strong influence on the detector's gain behavior. A method is presented in which a gain map is calculated without flat field measurements. Rather, a series of quick scattering measurements from an amorphous scatterer is used to calculate a gain map. The ability to rapidly obtain a gain map allows for a recalibration of an x-ray detector as needed without significant expenditure of either time or effort. Area detectors on the beamlines used, such as the Pilatus 2M CdTe or Varex XRD 4343CT, were found to have gains which drift slightly over timescales of several weeks or after exposure to high photon flux, suggesting the need to more frequently recalibrate for detector gain.