Photon interference x-ray absorption fine structure

We report about a fine structure in x-ray absorption spectra, named photon interference x-ray absorption fine structure $\left(\pi \mathrm{XAFS}\right).\mathrm{}$ $\pi \mathrm{XAFS}$ is due to the interference of x-rays inside the sample and extends across absorption edges. Using a platinum foil $\pi \mathrm{XAFS}$ was measured in a high precision absorption experiment. Excellent agreement with a theoretical $\pi \mathrm{XAFS}$ simulation is achieved in the energy range for above an absorption edge where photoelectron XAFS is negligible. $\pi \mathrm{XAFS}$ provides a method for determination of atomic structure on short- and long-range order scale.