Temperature analysis of X-ray Thomson scattering data

TL;DR

This paper presents a new, model-free method for accurately determining the temperature of complex materials from X-ray Thomson scattering data, even in the presence of experimental noise, with broad applications in high-energy density physics.

Contribution

The paper introduces a formally exact, model-independent approach for extracting temperature from scattering data, improving accuracy over previous methods.

Findings

Method successfully applied to synthetic and experimental data.

Robust against experimental noise.

Applicable across a wide temperature and wave number range.

Abstract

The accurate interpretation of experiments with matter at extreme densities and pressures is a notoriously difficult challenge. In a recent work [T.~Dornheim et al., Nature Comm. (in print), arXiv:2206.12805], we have introduced a formally exact methodology that allows extracting the temperature of arbitrarily complex materials without any model assumptions or simulations. Here, we provide a more detailed introduction to this approach and analyze the impact of experimental noise on the extracted temperatures. In particular, we extensively apply our method both to synthetic scattering data and to previous experimental measurements over a broad range of temperatures and wave numbers. We expect that our approach will be of high interest to a gamut of applications, including inertial confinement fusion, laboratory astrophysics, and the compilation of highly accurate equation-of-state databases.