X-ray Microtomography
National School on Neutron and X-ray Scattering August 14-28 2005
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
I = I0e-x
I0: Incoming intensity of X-rayI : Outgoing intensity of X-ray: linear X-ray attenuation
xI = I0e-(kxk..
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 LightMirror
Microtomography at APS Beamline 13-BMVarious 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?
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.