title: Evidence for out-of-equilibrium states in warm dense matter probed by x-ray Thomson scattering.
abstract: A recent and unexpected discrepancy between ab initio simulations and the interpretation of a laser shock experiment on aluminum, probed by x-ray Thomson scattering (XRTS), is addressed. The ion-ion structure factor deduced from the XRTS elastic peak (ion feature) is only compatible with a strongly coupled out-of-equilibrium state. Orbital free molecular dynamics simulations with ions colder than the electrons are employed to interpret the experiment. The relevance of decoupled temperatures for ions and electrons is discussed. The possibility that it mimics a transient, or metastable, out-of-equilibrium state after melting is also suggested.
authors: CEA, DAM, DIF 91297 Arpajon, France.
authors: Jean
authors: J
authors: Clérouin
authors: CEA, DAM, DIF 91297 Arpajon, France.
authors: Grégory
authors: G
authors: Robert
authors: CEA, DAM, DIF 91297 Arpajon, France.
authors: Philippe
authors: P
authors: Arnault
authors: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors: Christopher
authors: C
authors: Ticknor
authors: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors: Joel D
authors: JD
authors: Kress
authors: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors: Lee A
authors: LA
authors: Collins