Error evaluation and improved estimation of partial scattering functions in contrast variation small-angle neutron scattering
Koichi Mayumi
The Institute for Solid State Physics, The University of Tokyo, Tokyo, Japan
E-mail: kmayumi@issp.u-tokyo.ac.jp
Contrast-variation small-angle neutron scattering (CV-SANS) is a powerful tool to evaluate the structure of multi-component systems by decomposing the scattering intensities I measured with different scattering contrasts into partial scattering functions S of self- and cross-correlations between components. The measured I contains a measurement error ΔI, and ΔI results in an uncertainty in the partial scattering functions ΔS. However, the error propagation from ΔI to ΔS has not been quantitatively clarified. Recently, we have established deterministic and statistical approaches to determine ΔS from ΔI [1]. We have applied the two methods to (i) computational data for a core–shell sphere, and experimental CV-SANS data of (ii) clay/polyethylene glycol aqueous solutions and (iii) polyrotaxane solutions, and have successfully estimated the errors in S. The quantitative error estimation in S offers a strategy to optimize the combination of scattering contrasts to minimize error propagation. Also, we have improved the estimation of partical scattering functions S, based on Gaussian process regression using prior knowledge about the smoothness and flatness in Q dependence of S [2].
References :
[1] K. Mayumi, T. Oda, S. Miyajima, I. Obayashi, K. Tanaka, “Error evaluation of partial scattering functions obtained from contrast-variation small-angle neutron scattering”, Journal of Applied Crystallography, 58, 4 (2025). https://doi.org/10.1107/S1600576724010872
[2] I. Obayashi, S. Miyajima, K. Tanaka, K. Mayumi, “Enhanced estimation method for partial scattering functions in contrast variation small-angle neutron scattering via Gaussian process with prior knowledge of smoothness”, Journal of Applied Crystallography, in press
