1. Gene Ice and John Hunn ORNL
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. Triso Fuel Particles~800 mm-D
Xradia x-ray microtomography system provides nondestructive characterization of small objects
Triso Fuel Particles~800 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
Absorption
Diffraction Contrast
Cartilage on bone A: Absorption contrast; B. diffraction contrast
Bee head