An improved X-ray image plate detector for diffractometry

X-ray image plates have a number of advantages compared to conventional x-ray films due to their large dynamic range and high sensitivity. They need no chemical processing, since they allow the direct digitization of the x-ray information with a laser scanning system. Even compared with scintillation counters or other single element detectors, which are usually applied in diffractometry as directly digitizing detectors, image plates have the advantage of a simultaneous detection of all x-ray reflexes within its active area. Therefore the measuring time of an diffraction pattern is significantly reduced. However, the performance of an image plate detector system is strongly dependent on the performance of the image plate and of the scanning system. Here we report on a considerably improved type of image plate detector for diffractometry. It allows the fast digitization of the x-ray images with high resolution, high sensitivity and short repetition times. Examples for the use in structure analysis are given. The performance of the image plate detector is compared to other xray defectors such as the x-ray film and scintillation detectors. As a result the image plate detector reduces the time for the measurement of an diffraction pattern by a factor of about 100 compared to single element detectors. In addition, the effect of the thickness of the image plate on the resolution and efficiency of the x-ray image plates is investigated. The results indicate that the use of thin image plates improves the spatial resolution to about 50 mu m.