New Roughening data from Z

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New Roughening data from Z

• Presented by Craig Olson for
• Tina J. Tanaka
• HAPL Meeting Oct 27-28, 2004
• Princeton, NJ

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Old data from Surface profile Powder Metal
Tungsten
Mag 10X 2.3 J/cm2
1.3 J/cm2
Back in 2002, we thought that 2.3 J/cm2 was the
onset of roughening, and we did not see any at
1.3 J/cm2. We then started to do cross sections
to see changes in grain structure and realized
that we had a melt section at 2.3, but not at 1.3
J/cm2. The thick line was added to show the
interface between exposed (above) and unexposed
regions
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Calculations vs. Data from FIB Cross Sections
BUCKY calculation by Robert Peterson, LANL,
Fluence levels by Greg Rochau
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Roughening on Single shot of Z, 0.9
J/cm2Polycrystalline materials show more
roughening
Single Crystal
Powder Metal
Chemical Vapor Deposition
5X
100X
All of these samples were exposed to the same
shot, filter and debris. High magnification
images show that there is more roughening of the
polycrystalline material. Beryllium and steel
probably make up most of the (mountains). The
valleys in polycrystalline W may occur because of
the grain boundaries.
The threshold for roughening with X rays should
be lowered to 0.9J/cm2
Surface profile measurements by Justin Stolp,
Schafer Corp.