X-ray Microtomography National School on Neutron and X-ray Scattering August Group D Jiong Hua Vaibhav Kohli Soonjoo Seo Lu Zou Paul J. Sideris

X-ray Computed Microtomography Imaging tool using high flux at photon energies up to 100 keV. APS bending magnet source: 20 keV High resolution, 3D images of various porous media Characterization of fluid phases Transport of multiphase flow

Why Microtomography? Non-Invasive examination of the internal structure of objects Meteorites, fossils  valuable Interplanetary dust particles, soil aggregates  fragile Diamonds, hard minerals  time consuming Studies of pore network : pore distribution, size, topography, connectivity

Major Fields of Study Earth and Environmental Research High Pressure CMT (10 Gpa) Metal deposition in plant roots, minerals, meteorites Porosity Studies in Dehydraded-rehydrated media Multi Phase Fluids in Porous Media

Attenuation of X-rays Greater Attenuation X-rays Sample  xx I = I 0 e -  x I 0 : Incoming intensity of X-ray I : Outgoing intensity of X-ray  : linear X-ray attenuation    x I = I 0 e -(        k  x kk.. X-ray Computed Microtomography (CMT) gives 3D images of the X-ray attenuation coefficient.

Experimental Setup Microscope Objective CCD Camera Rotation Stage Sample  x Translation Stage YAG Scintillator X-rays Visible Light Mirror Microtomography at APS Beamline 13-BM Various stages align the sample with the X-ray beam and CCD camera YAG converts X-rays to visible light for imaging

System Under Investigation Material Silica beads pack in a cylindrical tube Two different fluids containing I and Cs Goal of Study What ions exist in the fluid? Where are the two types of liquids located? What are their domain sizes and distributions within the tube?

Data Processing – Image Reconstruction I’ (x’, y’, Θ) I (x, y, z)

Data Processing – X-ray Absorption I absorption edgeCs absorption edge

Conclusions CMT allows the identification of Soltrol® and aqueous CsCl in porous media. Aqueous CsCl is found in smaller amounts around inner wall of tube. X-ray tomography is a powerful and efficient tool for studying multiphase fluids in solids.

Acknowledgements  National School of Neutron and X-ray Scattering  DOE  Mark Rivers - University of Chicago, APS 13-BM  Clinton Willson - Louisiana State University