Synchrotron X-Ray Multi-Projection Imaging (XMPI) for High-Resolution 4D Characterization of Multiphase Flows
Abstract
Multiphase flows where particles, bubbles, or droplets are suspended in a fluid govern critical processes in biology, medicine, materials processing, and geophysics. However, observing their microscale dynamics in opaque systems has remained a fundamental challenge. We present Synchrotron X-ray Multi-Projection Imaging (XMPI), a novel approach enabling four-dimensional (3D+time) tracking of microparticles in dense suspension flows without requiring sample rotation. By capturing simultaneous projections from multiple angles using beam-split X-rays at synchrotron facilities, we resolve instantaneous particle positions and trajectories in opaque fluids such as blood. We demonstrate the potential of XMPI through individual particle tracking velocimetry (3D PTV) in dilute conditions, as well as multi-projection optical flow analysis in dense suspensions. The methodology provides otherwise inaccessible experimental validation for particle-resolved computational fluid dynamics models and allows, e.g., observation of inertial focusing effects and microstructural dynamics relevant to suspension rheology and biomedical flows. This work paves the way for high-resolution, time-resolved 4D imaging of complex multiphase flows across a range of scientific and industrial applications. Combining XMPI with recent AI-supported 4D reconstruction algorithms opens a new spatiotemporal frontier for high-speed, rotation-free microtomography.
Keywords
Cite
@article{arxiv.2412.09368,
title = {Synchrotron X-Ray Multi-Projection Imaging (XMPI) for High-Resolution 4D Characterization of Multiphase Flows},
author = {Tomas Rosén and Zisheng Yao and Jonas Tejbo and Patrick Wegele and Julia K. Rogalinski and Frida Nilsson and Kannara Mom and Zhe Hu and Samuel A. McDonald and Kim Nygård and Andrea Mazzolari and Alexander Groetsch and Korneliya Gordeyeva and L. Daniel Söderberg and Fredrik Lundell and Lisa Prahl Wittberg and Eleni Myrto Asimakopoulou and Pablo Villanueva-Perez},
journal= {arXiv preprint arXiv:2412.09368},
year = {2026}
}