High-resolution Fluorescence Imaging with X-ray Free-electron Pulses

Intensity correlation of x-ray fluorescence, based on the principle introduced by Hanbury Brown and Twiss, has been proposed for high-resolution imaging of a 3D arrangement of atoms. To explore the applicability of this imaging approach, we theoretically investigate fluorescence dynamics of non-periodic systems subject to femtosecond XFEL pulses over a range of pulse parameters from the linear to non-linear x-ray absorption regimes. In particular, we present the fluorescence intensity correlation computed from the angular distribution of the fluorescence patterns and discuss the impact of sample damage on retrieving high-resolution structural information and elemental contrast in heterogeneous systems.