Use of brilliance in powder diffraction: Towards high resolution kinetic studies

The performance of synchrotron undulator sources has improved considerably with improved construction techniques and has recently been reviewed by Diviacco and Walker however, these devices can only be fully utilized if used with fast detectors. The initial design of a high count rate curved linear position sensitive detector (PSD) for high resolution powder diffraction is described in this paper in conjunction with the advantages afforded by higher flux sources. This work is a development of the two dimensional detectors produced for small angle scattering. The specifications of the new detector are count rates in excess of 106, an angular resolution of 0.03° or better, sufficient energy resolution to reject the third harmonic from the incident beam and angular aperture of up to 60°. The new curved PSD has the potential, depending upon the angular range, to improve on the step scanning data collection times by a factor of 1000 because there is no dead time in driving and all data points in the powder diagram range can be collected simultaneously. The combination of more powerful sources and faster, high resolution detectors, makes new areas of research in high resolution kinetics possible.