Nearest-neighbor atom interference effect on bound-free opacity of hot dense gold plasma

Quantum interference, similar to Young double-slit interference, takes place between the photoionization processes of two same kind atoms when the nuclei separation is less than or comparable to the de Broglie wavelength of the ionized electrons. In dense plasma, the average nearest-neighbor atom distance maybe comparable to or even less than the wavelength of the outgoing electrons, the photoionization cross section of the atoms as well as the opacity of the plasma will be affected by this kind of interferences among atoms. In the present work, we first attain the nearest-neighbor distributions of the atoms in hot dense plasmas by performing an average-atom molecular dynamics (AAMD) simulation. Then, the effective total photoionization cross section is obtained by integrating the two atom interference effects over the nearest-neighbor distributions. At last, the bound-free and Rosseland mean opacities of Au plasmas at 100 eV and different densities show that the interference effects are considerable when the density is larger than 1 g/cm3.