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 ionelectron 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.

arXiv comment12 pages, 11 figures

References in corpus (7)

• X-Ray Thomson scattering without the Chihara decomposition
• Ionic and electronic transport properties in dense plasmas by orbital-free density functional theory
• Evidence for out-of-equilibrium states in warm dense matter probed by X-ray Thomson scattering
• Electron-ion and ion-ion potentials for modeling warm-dense-matter: applications to laser-heated or shock-compressed Al and Si
• Bypassing the malfunction junction in warm dense matter simulations
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Cited by in corpus (11)

• Nonempirical Semi-local Free-Energy Density Functional for Matter Under Extreme Conditions
• Accurate Temperature Diagnostics for Matter under Extreme Conditions
• Structural characteristics of strongly coupled ions in a dense quantum plasma
• Dynamical structure factor of strongly coupled ions in a dense quantum plasma
• Screening of a test charge in a free-electron gas at warm dense matter and dense non-ideal plasma conditions
• Ion Potential in Non-ideal Dense Quantum Plasmas
• Isochoric, isobaric and ultrafast conductivities of aluminum, lithium and carbon in the warm dense matter (WDM) regime
• Ion-ion dynamic structure factor, acoustic modes and equation of state of two-temperature warm dense aluminum
• Efficacy of the Radial Pair Potential Approximation for Molecular Dynamics Simulations of Dense Plasmas
• Equation of state, phonons, and lattice stability of ultra-fast warm dense matter
• Simple pair-potentials and pseudo-potentials for warm-dense matter and general applications