THE PERFORMANCE OF X-RAY DETECTORS BASED ON IMAGE PLATES. M. Thoms, R. Fasbender, N. Gloser, A. Kinne, A. Winnacker, University of Erlangen-Nürnberg, Institute for Material Science VI, Martensstr. 7, 91058 Erlangen, Germany

X-ray detectors, which are based on image plates are increasingly used in crystallography. The performance of these detectors and therewith the quality of the acquired data depends on two basic processes: The conversion of x-ray radiation into storage centers and the readout of the stored information. Both processes are influenced by characteristics of the image plate and the reader as well. These characteristics are for instance the thickness of the phosphor layer, the type of phosphor and its grain size, the laser intensity and the sensitivity of the utilized photodetector in the reader. The effect of these parameters on the image resolution, the noise of the image and the quantum efficiency of the detector and therewith on the quality of the data will be discussed.

It will be shown by examples, that a spatial resolution of 50um, a precision of the dose measurement better than 1% and an acquisition time of less than 40s for an image of 20x30cm² consisting of 17.5 million pixels can be reached in the case of an optimized detector.