Calibration and Application of an X-ray Image Intensifier/ Charge-Coupled Device Detector for Monochromatic Macromolecular Crystallography

Charge‐coupled device (CCD)‐based X‐ray detectors allow data to be collected much more quickly (~ 10 times) than with current on‐line imaging‐plate systems. At the ESRF, X‐ray image intensifier/CCD detector systems have been developed. These have great potential as fast read‐out detectors for macromolecular and other forms of crystallography. They are relatively large sensitive X‐ray detectors but have two inherent weaknesses: convex detection surfaces leading to spatial distortion and non‐uniformity of intensity response, and susceptibility to small changes in magnetic fields. A large improvement has been made to the accuracy obtained by non‐uniformity of response calibration and correction, using fluorescence from doped lithium borate glasses. Monochromatic macromolecular crystallography demonstration experiments with external user groups have shown that high‐quality results may be obtained under real experimental conditions.