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DOE OSTI · 1825252

Cross-correlation analysis of X-ray photon correlation spectroscopy to extract rotational diffusion coefficients

Hu, Zixi·Donatelli, Jeffrey J.·Sethian, James A.
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Abstract

Coefficients for translational and rotational diffusion characterize the Brownian motion of particles. Emerging X-ray photon correlation spectroscopy (XPCS) experiments probe a broad range of length scales and time scales and are well-suited for investigation of Brownian motion. While methods for estimating the translational diffusion coefficients from XPCS are well-developed, there are no algorithms for measuring the rotational diffusion coefficients based on XPCS, even though the required raw data are accessible from such experiments. In this paper, we propose angular-temporal cross-correlation analysis of XPCS data and show that this information can be used to design a numerical algorithm (Multi-Tiered Estimation for Correlation Spectroscopy [MTECS]) for predicting the rotational diffusion coefficient utilizing the cross-correlation: This approach is applicable to other wavelengths beyond this regime. We verify the accuracy of this algorithmic approach across a range of simulated data.

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97 MATHEMATICS AND COMPUTINGX-ray photon correlation spectroscopyangular cross-correlationcorrelation spectroscopyrotational diffusionspeckle pattern analysis

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Hu, Zixi, Donatelli, Jeffrey J., Sethian, James A.. 2021-08-18. Cross-correlation analysis of X-ray photon correlation spectroscopy to extract rotational diffusion coefficients. https://doi.org/10.1073/pnas.2105826118

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