Accurate temperature diagnostics for matter under extreme conditions

The experimental investigation of matter under extreme densities and temperatures, as in
astrophysical objects and nuclear fusion applications, constitutes one of the most active frontiers at
the interface of material science, plasma physics, and engineering. The central obstacle is given by
the rigorous interpretation of the experimental results, as even the diagnosis of basic parameters like
the temperature T is rendered difficult at these extreme conditions. Here, we present a simple,
approximation-free method [1,2] to extract the temperature of arbitrarily complex materials in
thermal equilibrium from X-ray Thomson scattering experiments, without the need for any
simulations or an explicit deconvolution. Our paradigm can be readily implemented at modern
facilities and corresponding experiments will have a profound impact on our understanding of warm
dense matter and beyond, and open up a variety of appealing possibilities in the context of
thermonuclear fusion, laboratory astrophysics, and related disciplines.
[1] T. Dornheim, M. Böhme, D. Kraus, T. Döppner, Th. Preston, Zh. Moldabekov, and J. Vorberger,
Accurate temperature diagnostics for matter under extreme conditions, Nature Comm. 13, 7911
(2022)
[2] T. Dornheim, M. Böhme, D. Chapman, D. Kraus, T. Döppner, Th. Preston, Zh. Moldabekov, and
J. Vorberger, Temperature analysis of X-ray Thomson scattering data, arXiv:2212.10510