3D XPCS technique using hard X-ray Optical Correlator
We have demonstrated a proof-of-principle study of 3D Photon Correlation Spectroscopy (3D-PCS) in the hard X-ray regime at PETRA III storage ring. Until now 3D -PSC was performed only with laser based lab sources. Thanks to development of hard X-ray optics utilised in split-and-delay devices one can attempt to carry out cross correlation XPCS experiments. Our study has been carried out at the beamline P10 using hard X-ray cross-correlator. Speckle patterns were measured from a model system of silica colloidal nanoparticles in polypropylene glycol at room temperature. Our cross-correlation curves show excellent agreement with the auto-correlation XPCS results. Our results provide basis for further studies on highly dense systems where multiple scattering might have to be considered in conventional XPCS correlation functions.
Optics Letters 47, 293-296, 2022
