Speckle Structure in Small-Angle Coherent X-ray Scattering

Small-angle coherent X-ray scattering measurements on a polymer gel and on a single crystal of Al-9at.% Li are reported. Speckle structures were recorded using a direct-illumination CCD camera. A speckle intensity fluctuation of ~20% was observed. Time and space statistics for the signal provided estimates of the coherence effects and the measurements demonstrate the wavevector dependence of the coherence effects. Preliminary intensity-fluctuation spectroscopy was performed for Al-Li.