1. Craig Olson, Tina Tanaka, Tim Renk, Greg Rochau, Robert Peterson
Exposures of FW candidate materials on Z (x-rays - single shot) and on RHEPP (ions - 100s of shots) Introduction
Craig Olson, Tina Tanaka, Tim Renk, Greg Rochau, Robert Peterson
HAPL Meeting at UCLA
June 2-3, 2004
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

2. Philosophy of using x-rays on Z to test laser IFE dry-wall materials
Then: Use as single-shot test bed for initial screening of candidate wall materials,
and compare with Bucky code calculations
Advantages: wide fluence range ( 1 J/cm2 to  1000 J/cm2)
very uniform fluence (large distance from “point source”)
~1 keV x-rays for tungsten wire array
tailored line radiation to 4 keV, and higher, if wanted
Disadvantages: debris, exact spectra, add-on shots hard to acquire
Now: Finalize understanding of roughening
Normalize results on Z with results on XAPPER
Test materials with many keV spectra (closest to threat spectra) if desired
Test “final” candidate material

3. Tungsten exposure to x-rays on Z shows that x-ray damage should not be a problem (single shot)
threat threat
(154 MJ) (400 MJ)

4. Philosophy of using ions on RHEPP to test laser IFE dry-wall materials
Then: Use as single-shot test bed for initial screening of candidate wall materials,
and compare with Bucky code calculations
Advantages: power plant relevant ion fluences (up to ~10 J/cm2)
uniform fluence, choice of ions
effect of Bragg peak
easy access, fast turn around
Disadvantages: ~ 100 ns (whereas threat is ~ s)
Now: Principle facility for ion testing of candidate wall materials for HAPL
Extensive studies of ablation, roughening, cracking, valleys, exfoliation, etc.
Extensive studies of aging (above ~ 100 shots)
100s to 1000 or more shots
Extensive range of candidate materials are being tested

5. FW material exposure to ions on RHEPP shows that ion damage is still an issue
Ablation
Depth
(mm)
Net Ablation
No net ablation, but
surface roughening
F(J/cm2)
Threshold for roughening
Threshold for
ablation
Threats: 154 MJ MJ
8.5 J/cm J/cm2
(1.82 J/cm2) (4.54 J/cm2)
For W:
 1.25 J/cm2
 6 J/cm2
 2 J/cm2
(current tests)