X-ray thermal diffuse scattering as a texture-robust diagnostic of temperature

Measuring the temperature of dynamically compressed matter remains one of the longest-standing problems in the field. We recently demonstrated [1] single-shot temperature diagnosis of shock-loaded copper using measurements of its Debye-Waller factor (DWF) derived from its thermal diffuse scattering (TDS) signal at the European XFEL. Unlike conventional, Bragg-peak-based DWF measurements, the TDS-derived measurement is largely insensitive to the sample’s crystallographic texture. To demonstrate this, we present a texture-aware model of TDS from a cubic polycrystal based on Warren’s formalism [2]. By modelling samples with a rolling texture, we demonstrate that: with sufficient angular coverage, the TDS signal is unchanged by sample orientation and strongly resembles the signal from a perfectly random powder; shot-to-shot fluctuations in the TDS signal resulting from grain-sampling statistics are at the percent level; and TDS is largely unchanged even following texture evolution caused by plastic deformation. We conclude that TDS is robust against texture variation, making it a flexible temperature diagnostic applicable just as well to off-the-shelf commercial foils as to ideal powders.

[1] J. S. Wark et al., arXiv:2501.02940 (2025)

[2] B. E. Warren, Acta. Crystallog. 6, 803 (1953)