Gene Ice and John Hunn

1
3D Tomography of Low-Z Spherical Shells

• Gene Ice and John Hunn
• ORNL

Over the past several years Gene Ice of ORNL has
been developing x-ray optics and detectors and
working closely with X-radia corporation which
develops microtomography imaging systems. This
presentation reviews recent developmental work to
image 3D spherical shells, two examples - Gas
cooled reactor TRISO fuel (layered SiC-C on
fuel kernal) - Layered target provided by
LLNL
2
Xradia x-ray microtomography system provides
nondestructive characterization of small objects
Triso Fuel Particles800 mm-D

• Major advance
• Resolution 1 mm (smaller defects)
• Works with low Z samples
• Quantitative shell dimensions
• State-of-the-art software
• Ideally suited for inertial targets
• Thickness/uniformity C-H shell
• Au shell density

Xradia image
previous state-of- the-art
Au
C-H
Major improvement possible!
DT
4000mm
3
Surrogate IFE Target Mounting and Scanning
Bottom half of target rigidly mounted in
resin. Following movies give low resolution
3D scans taken in 80 seconds. Movies are a
series of planar slices taken first in the plane
of the image to the left (x-z) then a polar image
(x-y)
z
x
y
glue
Courtesy of X-radia and Gene Ice. Surrogate
target provided by LLNL.
4
80 Second Scan Series of x-z planes
Courtesy of X-radia and Gene Ice
5
80 Second Scan Series of polar image x-y
planes View starts at glue and moves to the North
Pole
Courtesy of X-radia and Gene Ice
6
High-Resolution Image
None of the movies or this high-resolution
image are optimized for resolution. Image
resolution of standard optics is submicron. In
order to scan this large target rapidly spatial
resolution of 1 micron was applied. Note
that in addition to this imaging, the software
contains precise information on local density and
precise geometric information (asphericity,
non-uniformity, etc)
Courtesy of X-radia and Gene Ice
7
Even better performance possible Diffraction
contrast dramatically improves contrast in low Z
materials

• Small beam deflections analyzed by crystal optics
• Optimized Kirkpatrick-Baez collimating optics
  essential for laboratory sources

8
Diffraction contrast imaging - sensitivity to
inhomogeneities low Z materials

• Orders of magnitude better contrast
• Particularly sensitive to cracks, voids,
  inclusions

4mm
Cartilage on bone A Absorption contrast B.
diffraction contrast
Bee head