Area detector based photon correlation in the regime of short data batches: Data reduction for dynamic x-ray scattering

A method for reducing time sequences of raw scattering images to intensity time-autocorrelation functions is presented. The procedure is based on the use of a charge coupled device (CCD) area detector, and optimized for operating in the regime of short data batches. Its application to x-ray photon correlation spectroscopy (XPCS) measurements is described in detail. Using a slow-scan CCD, we explain how to achieve data acquisition on a 30 ms or faster time scale, while simultaneously acquiring data from many coherence areas in parallel. The statistical uncertainties of the acquired XPCS data are quantified experimentally, and compared to the theoretically expected noise levels of the correlation functions. (C) 2000 American Institute of Physics. [S0034-6748(00)03509-7].