title: Pair potentials for warm dense matter and their application to x-ray Thomson scattering in aluminum and beryllium.
abstract: Ultrafast laser experiments yield increasingly reliable data on warm dense matter, but their interpretation requires theoretical models. We employ an efficient density functional neutral-pseudoatom hypernetted-chain (NPA-HNC) model with accuracy comparable to ab initio simulations and which provides first-principles pseudopotentials and pair potentials for warm-dense matter. It avoids the use of (i) ad hoc core-repulsion models and (ii) "Yukawa screening" and (iii) need not assume ion-electron thermal equilibrium. Computations of the x-ray Thomson scattering (XRTS) spectra of aluminum and beryllium are compared with recent experiments and with density-functional-theory molecular-dynamics (DFT-MD) simulations. The NPA-HNC structure factors, compressibilities, phonons, and conductivities agree closely with DFT-MD results, while Yukawa screening gives misleading results. The analysis of the XRTS data for two of the experiments, using two-temperature quasi-equilibrium models, is supported by calculations of their temperature relaxation times.
authors.affiliation: Département de Physique and Regroupement Québécois sur les Matériaux de Pointe, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, Québec, Canada H3C 3J7.
authors.forename: L
authors.initials: L
authors.lastname: Harbour
authors.affiliation: National Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6.
authors.forename: M W C
authors.initials: MW
authors.lastname: Dharma-Wardana
authors.affiliation: National Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6.
authors.forename: D D
authors.initials: DD
authors.lastname: Klug
authors.affiliation: Département de Physique and Regroupement Québécois sur les Matériaux de Pointe, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, Québec, Canada H3C 3J7.
authors.forename: L J
authors.initials: LJ
authors.lastname: Lewis