Differential phase contrast for quantitative imaging and spectro-microscopy at a nanoprobe beamline

DOI: 10.1107/S1600577522010633

Authors: Paul D. Quinn (Diamond Light Source) , Fernando Cacho-Nerin (Diamond Light Source) , Miguel A. Gomez-Gonzalez (Diamond Light Source) , Julia E. Parker (Diamond Light Source) , Timothy Poon (Diamond Light Source) , Jessica M. Walker (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Synchrotron Radiation , VOL 30

State: Published (Approved)
Published: December 2022
Diamond Proposal Number(s): 28142

Abstract: The interaction of a focused X-ray beam with a sample in a scanning probe experiment can provide a variety of information about the interaction volume. In many scanning probe experiments X-ray fluorescence (XRF) is supplemented with measurements of the transmitted or scattered intensity using a pixelated detector. The automated extraction of different signals from an area pixelated detector is described, in particular the methodology for extracting differential phase contrast (DPC) is demonstrated and different processing methods are compared across a range of samples. The phase shift of the transmitted X-ray beam by the sample, extracted from DPC, is also compared with ptychography measurements to provide a qualitative and quantitative comparison. While ptychography produces a superior image, DPC can offer a simple, flexible method for phase contrast imaging which can provide fast results and feedback during an experiment; furthermore, for many science problems, such as registration of XRF in a lighter matrix, DPC can provide sufficient information to meet the experimental aims. As the DPC technique is a quantitative measurement, it can be expanded to spectroscopic studies and a demonstration of DPC for spectro-microscopy measurements is presented. Where ptychography can separate the absorption and phase shifts by the sample, quantitative interpretation of a DPC image or spectro-microscopy signal can only be performed directly when absorption is negligible or where the absorption contribution is known and the contributions can be fitted.

Journal Keywords: differential phase contrast; DPC; ptychography; nanoprobe; spectro-microscopy

Subject Areas: Technique Development, Physics


Instruments: I14-Hard X-ray Nanoprobe

Added On: 07/12/2022 09:37

Documents:
Journal of Synchrotron Radiation - 2022 - Quinn - Differential phase contrast for quantitative imaging and.pdf

Discipline Tags:

Physics Technique Development - Physics

Technical Tags:

Phase Contrast Imaging