Statistical Analysis of X-ray Speckle at the NSLS

We report a statistical analysis of the static speckle produced by illuminating a disordered aerogel sample by a nominally coherent x-ray beam at wiggler beamline X25 at the National Synchrotron Light Source. The results of the analysis allow us to determine that the coherence delivered to the X25 hutch is within 35% of what is expected. The rate of coherent photons is approximately two times smaller than expected on the basis of the X25 wiggler source brilliance.