Laboratory astroparticle physics

Abstract:

We develop a new theoretical approach that demonstrates the abilities of elastic X-ray scattering to yield thermodynamic, structural, and mixing properties of dense matter with multiple ion species. The novel decomposition of the electron structure factor in multi-component systems provides the basis to study dense mixtures as found in giant gas planets or during inertial confinement fusion. We show that the scattering signal differs significantly between single species, microscopic mixtures, and phase-separated fluids. Thus, these different phases can be distinguished experimentally via elastic X-ray scattering. © 2011 Europhysics Letters Association.

Abstract:

We reply to the comment by Iglesias [HEDP, XXX] regarding our implementation of a solid-state pseudopotential in a model for the calculation of the free--free opacity in warm-dense aluminum [HEDP 5(2009), 124-131]. Some further details are given describing the method used to determine the adjustable parameter in the pseudopotential and several important limitations are discussed. © 2010 Elsevier B.V.

Abstract:

We show that the hydrodynamic description can be applied to modeling the ionic response in dense plasmas for a wide range of length scales that are experimentally accessible. Using numerical simulations for the Yukawa model, we find that the maximum wave number k(max) at which the hydrodynamic description applies is independent of the coupling strength, given by k(max)λ(s)≃0.43, where λ(s) is the ionic screening length. Our results show that the hydrodynamic description can be used for interpreting x-ray scattering data from fourth generation light sources and high power lasers. In addition, our investigation sheds new light on how the domain of validity of the hydrodynamic description depends on both the microscopic properties and the thermodynamic state of fluids in general.