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Title: Erosion/redeposition analysis of the ITER first wall with convective and non-convective plasma transport.

Abstract

No abstract prepared.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
914842
Report Number(s):
ANL/MCS/JA-57338
Journal ID: ISSN 1070-664X; PHPAEN; TRN: US0803393
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys. Plasmas; Journal Volume: 13; Journal Issue: 2006
Country of Publication:
United States
Language:
ENGLISH
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; FIRST WALL; PLASMA; TRANSPORT

Citation Formats

Brooks, J. N., Allain, J. P., Rognlien, T., Mathematics and Computer Science, and LLNL. Erosion/redeposition analysis of the ITER first wall with convective and non-convective plasma transport.. United States: N. p., 2006. Web. doi:10.1063/1.2401610.
Brooks, J. N., Allain, J. P., Rognlien, T., Mathematics and Computer Science, & LLNL. Erosion/redeposition analysis of the ITER first wall with convective and non-convective plasma transport.. United States. doi:10.1063/1.2401610.
Brooks, J. N., Allain, J. P., Rognlien, T., Mathematics and Computer Science, and LLNL. Sun . "Erosion/redeposition analysis of the ITER first wall with convective and non-convective plasma transport.". United States. doi:10.1063/1.2401610.
@article{osti_914842,
title = {Erosion/redeposition analysis of the ITER first wall with convective and non-convective plasma transport.},
author = {Brooks, J. N. and Allain, J. P. and Rognlien, T. and Mathematics and Computer Science and LLNL},
abstractNote = {No abstract prepared.},
doi = {10.1063/1.2401610},
journal = {Phys. Plasmas},
number = 2006,
volume = 13,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
  • Sputtering erosion/redeposition is analyzed for IAEA [Report GA10FDR1-01-07-13 (2001)] plasma facing components, with scrape-off layer (SOL) plasma convective radial transport and nonconvective (diffusion-only) transport. The analysis uses the UEDGE code [T .D. Rognlien et al., J. Nucl. Mater. 196, 347 (1992)] and DEGAS code [D. P. Stotler et al., Contrib. Plasma Phys. 40, 221 (2000) ] to compute plasma SOL profiles and ion and neutral fluxes to the wall, TRIM-SP code [J. P. Biersack, W. Eckstein, J. Appl. Phys. A34, 73 (1984)] to compute sputter yields, and the REDEP/WBC code package [J. N. Brooks, Fusion Eng. Des. 60, 515 (2002)]more » for three-dimensional kinetic modeling of sputtered particle transport. Convective transport is modeled for the background plasma by a radially varying outward-flow component of the fluid velocity, and for the impurity ions by three models designed to bracket existing models/data. Results are reported here for the first wall with the reference beryllium coating and an alternative tungsten coating. The analysis shows: (1) sputtering erosion for convective flow is 20-40 times higher than for diffusion-only but acceptably low ({approx}0.3 nm/s) for beryllium, and very low ({approx}0.002 nm/s) for tungsten; (2) plasma contamination by wall sputtering, with convective flow, is of order 1% for beryllium and negligible for tungsten; (3) wall-to-divertor beryllium transport may be significant ({approx}10%-60% of the sputtered Be current); (4) tritium co-deposition in redeposited beryllium may be high ({approx}1-6 gT/400 s pulse)« less
  • Erosion and redeposition of sputtered material from a limiter and divertor were analyzed using the REDEP computer code. Both low- and high-Z materials were examined for a wide range of plasma edge temperatures. Redeposition rates are high in most cases, and net erosion rates are predicted to be much smaller than the gross rates. The limiter front face and the entire divertor plate have similar erosion properties. The lifetime of both surfaces depends critically on the redeposition process; under certain conditions relatively long lifetimes may be obtainable.
  • We analyze a DIII-D tokamak experiment where two tungsten spots on the removable DiMES divertor probe were exposed to 12 s of attached plasma conditions, with moderate strike point temperature and density (~20 eV, ~4.5 × 10 19 m –3), and 3% carbon impurity content. Both very small (1 mm diameter) and small (1 cm diameter) deposited samples were used for assessing gross and net tungsten sputtering erosion. The analysis uses a 3-D erosion/redeposition code package (REDEP/WBC), with input from a diagnostic-calibrated near-surface plasma code (OEDGE), and with focus on charge state resolved impinging carbon ion flux and energy. Themore » tungsten surfaces are primarily sputtered by the carbon, in charge states +1 to +4. We predict high redeposition (~75%) of sputtered tungsten on the 1 cm spot—with consequent reduced net erosion—and this agrees well with post-exposure DiMES probe RBS analysis data. As a result, this study and recent related work is encouraging for erosion lifetime and non-contamination performance of tokamak reactor high-Z plasma facing components.« less