Theoretical study of laser heating and dissociation reactions in solids using ultrafast time-resolved x-ray diffraction

A theory of ultrafast time-resolved x-ray diffraction is presented. We show that for the case in which vibrational relaxation is fast, the x-ray diffraction intensities in pulse laser heating are determined by the Debye–Waller factor. We also show how the scattering intensities of the diffraction spots change with the position of the dissociating atoms in a time-resolved x-ray diffraction experiment studying dissociation reactions in solids. Our results show that the scattering intensities change in both the fully dissociated and the partially dissociated cases, and that time-resolved x-ray diffraction could be a useful tool in probing dissociation reactions in solids.