1. Exposures of Candidate First Wall Materials C.L. Olson, T.J. Tanaka, T.J. Renk, G.A. Rochau Sandia National Laboratories, Albuquerque, NM R.R. Peterson Los Alamos National Laboratory, Los Alamos, NM & University of Wisconsin, Madison, Wisconsin HAPL Program Workshop Georgia Institute of Technology Atlanta, Georgia February 5-6, 2004 Supported by NRL by the HAPL program by DOE NNSA DP Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

2. Regimes of FW Materials Response Studies for x-rays and ions Ablation Depth (  m) F(J/cm 2 ) Net Ablation No net ablation, but surface roughening Threshold for ablation Threshold for roughening Goal is to find and understand roughening threshold x-rays: single-shot heated samples on Z ions: multiple-shot heated samples on RHEPP

3. test roughening phenomena in heated samples on RHEPP (many shots) examine potential mechanisms for roughening: surface stress/yield at below melt temperatures, strain-rate and grain size effects, etc. establish threshold for roughening Strategy for use of RHEPP and Z to test FW materials Ion fluence for HAPL dry wall is an issue - present emphasis is to use ion beams on RHEPP (many shots) for extensive testing, and modeling with Bucky: X-ray fluence for HAPL dry wall does not appear to be an issue - but needs to be verified on Z use RHEPP/Bucky results to narrow list of candidate materials test best candidate materials on Z to verify threshold for roughening heater for 1000° C, new filtered Z spectra

4. Least Damaged Case Still has 2.5  m of Yielded Material BUCKY example

5. BUCKY Is Being Modeled to Include Plastic Flow 1.Work presented in September 2003 used post-processing of BUCKY-produced material temperature profiles with temperature dependant properties to show that W experiences yielding at low ion fluences. 2.Of course, the yielding material flows, which was not included in the work presented in September. Flow may be fast enough that strain-rate is important. 3.BUCKY needs proper Equations-of State to model plastic flow. 4.Developed in a manner closely linked to RHEPP and Z Experiments. Cu and Ti have not experienced the same roughening on RHEPP as W. BUCKY will be run on all three materials to validate BUCKY models and to understand different behaviors.

6. Proper Solid/Liquid EOS is Key to Modeling Plastic Flows with BUCKY 1.Mie-Grüneisen EOS (Am., J. Phys. 67, 1105 (1999)) is in BUCKY and being tested to predict plastic flow with thermal and shock effects. It is a thermodynamically consistent EOS. 2.M-G EOS could be adapted to include strain rate effects on yield stress and cohesive energy. 3.Steinberg-Guinan EOS (UCRL-MA-106439 (1991)) is a model that includes strain-rate effects. S-G parameters are tabulated for many materials including Cu, Ti-6Al-4V, and W. 4.We plan to add S-G EOS to BUCKY as an option. 5.We need good static high temperature properties to test models.

7. Next Talks Exposure to ions on RHEPP - Tim Renk 700 keV N or He ions multiple exposures of heated tungsten samples various fluences: 1.25 - 6 J/cm 2 FIB-XTEM analysis of powder met tungsten Exposure to x-rays on Z - Tina Tanaka x-ray energy ~ 1100 eV multiple heated tungsten samples various fluences: 1.0 - 2.5 J/cm 2 initial results