X-ray scattering as a probe for warm dense mixtures and high-pressure miscibility

TL;DR

This paper demonstrates how elastic x-ray scattering can be used to analyze the microscopic mixing and composition of dense, multi-ion-species materials under high pressure, providing a new diagnostic approach.

Contribution

It introduces a novel method utilizing partial structure factors from ab initio simulations to interpret elastic scattering signals in dense mixtures.

Findings

Scattering signals differ notably between pure, mixed, and separated fluid states.

The approach effectively distinguishes microscopic mixing in dense hydrogen-beryllium and hydrogen-helium.

Provides insights into high-pressure dense matter composition and mixing behavior.

Abstract

We demonstrate the abilities of elastic x-ray scattering to yield information on dense matter with multiple ion species and on the microscopic mixing in dense materials. Based on partial structure factors from ab initio simulations, a novel approach for the elastic scattering feature is applied to dense hydrogen-beryllium and hydrogen-helium mixtures. The scattering signal differs significantly between single species, real microscopic mixtures, and two separate fluids in the scattering volume.