2D anisotropic scattering pattern fitting using a novel Monte Carlo method: Initial results

TL;DR

This paper extends a Monte Carlo scattering pattern fitting method to anisotropic 2D data, enabling form-free retrieval of size and orientation distributions of ellipsoids with uncertainty estimates.

Contribution

It introduces an adaptation of a Monte Carlo method for fitting anisotropic 2D scattering patterns, including disorientation effects and distribution retrieval.

Findings

Successfully fits anisotropic 2D scattering data

Retrieves size and orientation distributions of ellipsoids

Highlights the need for morphological restrictions for unique solutions

Abstract

Recently, a Monte Carlo method has been presented which allows for the form-free retrieval of size distributions from isotropic scattering patterns, complete with uncertainty estimates linked to the data quality. Here, we present an adaptation to this method allowing for the fitting of anisotropic 2D scattering patterns. The model consists of a finite number of non-interacting ellipsoids of revolution (but would work equally well for cylinders), polydisperse in both dimensions, and takes into account disorientation in the plane parallel to the detector plane. The method application results in three form-free distributions, two for the ellipsoid dimensions, and one for the orientation distribution. It is furthermore shown that a morphological restriction is needed to obtain a unique solution.