Materials Studies on Z (x-rays) and RHEPP (ions) C.L. Olson, T.J.Tanaka, T.J. Renk, G.A.Rochau, M.A. Ulrickson Sandia National Laboratories, Albuquerque, NM M.Thompson, Cornell University, Ithaca, NY F. Davies, KTech, Albuquerque, NM P. Peterson, University of California, Berkeley, CA R.R. Peterson*, I. Golovkin, D. Haynes, G. Kulcinski, University of Wisconsin *Los Alamos National Laboratory, Los Alamos, NM M.S. Tillack, R.A. Raffray, F. Najmabadi, University of California, San Diego, CA T.R. Knowles, Energy Sciences Laboratories, Inc., San Diego, CA HAPL Meeting at NRL December 5-6, 2002 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.

Regimes of IFE 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 Goals (for each material): examine net ablation to validate codes find threshold for ablation understand roughening find threshold for roughening Threshold for roughening

X-rays and ions deposit energy with different spatial profiles X-rays (keV) Ions (  MeV) I -  E/  x photoelectric absorption of photons photons removed from flux I decreases exponentially absorption length R = (  ) -1 penetrates beyond R ion collisions with electrons ions slow down continuously |-  E/  x| increases to Bragg peak range is R essentially no penetration beyond R R R

Need to reproduce: (1) specific energy deposition S =  E/  V  F(J/cm 2 )/R(g/cm 2 ) (2) temporal profile S(t) [  S/  t, pulse width,…) rate of rise competes with thermal conductivity (3) spatial profile S(x) [deposition profile,…] deposition scale length compared to grain size, impurity scale size,… temperature gradients in deposition region Materials response testing should accurately reproduce specific energy deposition in candidate materials Z and RHEPP can replicate the conditions in IFE chamber walls Though there are some differences between IFE target spectra and Z and RHEPP, the experiments study the most important issues The surface temperature histories and temperature profiles are similar

Chamber Materials Response Program (Z and RHEPP) FY02 SNL $162k Overall coordination Olson Z experiments and x-ray spectra Tanaka, Rochau RHEPP experiments Renk Cornell $0k Temperature diagnostic on RHEPP Thompson U. Wisconsin $90k Bucky simulations of Z and RHEPP Peterson*, Golovkin (*LANL) Haynes, Kulcinski ESLI $23k Carbon velvets Knowles UCSD $65k Temperature diagnostic for RHEPP Tillack, Rafray, and materials suggestions Najmabadi UCB $42k Flibe samples, calculations Peterson K-Tech $23k Data-base of materials on Z Davies _____ $405k

Summary of exposures of IFE candidate first wall materials X-ray threat does not appear to be a problem Ion threat does appear to be a problem

UCSD contributions to materials testing  W materials and test plan W-1%La 2 O 3 supplied Plansee W-Re alloys explored, not purchased due to cost Working with PPI now to obtain samples  Search for innovative materials Exploration of nanoporous materials, collaboration with PPI Support of ESLI C-fiber development effort  Ultra-fast in-situ optical thermometer Prototype constructed, testing underway “Fieldable” version, suitable for delivery to SNLA, now under development 100 nm Plasma- spray alumina from nano- size particles (PPI) Vacuum plasma sprayed W from 3  m particle size (PPI) 20  m

UC Berkeley Materials Response Research X-ray ablation of molten salts –Samples of LiF have been exposed at 41 J/cm 2 Predicted 2.8  m ablation matches  m measured with LiF –Samples of Flibe have been prepared for x-ray experiments Now awaiting availability of Z shots –Flibe EOS work is underway Experiments are now measuring BeF2 vapor pressure, will soon measure Flibe vapor pressure and composition Improved models for vapor/liquid equilibrium are being developed Improved EOS for ABLATOR is being incorporated into the TSUNAMI code –High fluence (>1000 J/cm 2 ) data for lithium will soon be available KTech report is in preparation UCB will validate ABLATOR and TSUNAMI with this new data Scaling studies for dry-wall response in the ETF –UC Berkeley will be initiating new research to study the scaling of dry-wall chamber response phenomena with target yield, chamber dimensions, and chamber repetition rate –Will result in a range of scaling options for the laser ETF chamber that will permit accelerated, reduced cost component testing Example of cast and diced Flibe sample 5 mm LiF at 41 J/cm 2 with ablation step

Chambers Phase I Goals 1.Develop a viable first wall concept for a fusion power plant. 2.Produce a viable “point design” for a fusion power plant UCSD Wisconsin SNL ORNL LLNL UCSD Long term material issues are being resolved. Example- Ion exposures on RHEPP

Objectives for Materials Development over the next three years FY03 Establish the capability for heated samples on Z Establish the use of a shutter on Z to eliminate the debris issue Enhance scheduling of add-on shots on Z Establish options for x-ray spectra for Z and Saturn Continue testing of materials on Z (and start on Saturn as appropriate) Establish the capability for heated samples on RHEPP Establish enhanced diagnostics on RHEPP [T(t), etc. ] Continue testing of materials on RHEPP Explore engineered materials (e.g., coated carbon velvets)

Objectives for Materials Development over the next three years FY04, FY05 Establish a data base of materials tested on Z to show that thresholds for x-ray roughening and ablation are below the expected target threat spectra Establish a data base of materials tested on RHEPP to determine the gap between the thresholds for ion roughening and ablation and the expected target threat spectra Explore new materials to minimize or eliminate the gap Examine wetted-wall and thick-liquid wall materials such as Flibe, Flinabe, Li, PbLi, and surrogates such as LiF.

Next Talks Z Experiments Tina Tanaka (SNL) 15 min RHEPP Experiments Tim Renk (SNL) 20 min. Bucky Simulations of Z and RHEPP Robert Peterson (LANL and U. Wisc.) 15 min.