SPECKLE STRUCTURE IN SMALL-ANGLE COHERENT X-RAY-SCATTERING

Small-angle coherent X-ray scattering measurements on a polymer gel an d on a single crystal of Al-9at.% Li are reported. Speckle structures were recorded using a direct-illumination CCD camera. A speckle intens ity fluctuation of similar to 20% was observed. Time and space statist ics for the signal provided estimates of the coherence effects and the measurements demonstrate the wavevector dependence of the coherence e ffects. Preliminary intensity-fluctuation spectroscopy was performed f or Al-Li.