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Title: Plasma Interactions with Mixed Materials and Impurity Transport

Abstract

The project brings together three discipline areas at LLNL to develop advanced capability to predict the impact of plasma/material interactions (PMI) on metallic surfaces in magnetic fusion energy (MFE) devices. These areas are (1) modeling transport of wall impurity ions through the edge plasma to the core plasma, (2) construction of a laser blow-off (LBO) system for injecting precise amounts of metallic atoms into a tokamak plasma, and (3) material science analysis of fundamental processes that modify metallic surfaces during plasma bombardment. The focus is on tungsten (W), which is being used for the ITER divertor and in designs of future MFE devices. In area (1), we have worked with the University of California, San Diego (UCSD) on applications of the UEDGE/DUSTT coupled codes to predict the influx of impurity ions from W dust through the edge plasma, including periodic edge-plasma oscillations, and revived a parallel version of UEDGE to speed up these simulations. In addition, the impurity transport model in the 2D UEDGE code has been implemented into the 3D BOUT++ turbulence/transport code to allow fundamental analysis of the impact of strong plasma turbulence on the impurity transport. In area (2), construction and testing of the LBO injection systemmore » has been completed. The original plan to install the LBO on the National Spherical Torus Experiment Upgrade (NSTX-U) at Princeton and its use to validate the impurity transport simulations is delayed owing to NSTX-U being offline for substantial magnetic coil repair period. In area (3), an analytic model has been developed to explain the growth of W tendrils (or fuzz) observed for helium-containing plasmas. Molecular dynamics calculations of W sputtering by W and deuterium (D) ions shows that a spatial blending of interatomic potentials is needed to describe the near-surface and deeper regions of the material.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE Laboratory Directed Research and Development (LDRD) Program
OSTI Identifier:
1332472
Report Number(s):
LLNL-TR-707266
TRN: US1700724
DOE Contract Number:  
AC52-07NA27344
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 36 MATERIALS SCIENCE; NSTX DEVICE; PLASMA WAVES; TRANSPORT THEORY; IMPURITIES; IONS; HELIUM; TUNGSTEN; DEUTERIUM; MOLECULAR DYNAMICS METHOD; COMPUTERIZED SIMULATION; SURFACES; NEUTRAL ATOM BEAM INJECTION; PERIODICITY; TURBULENCE; DESIGN; DIVERTORS; DUSTS; LASER RADIATION; POTENTIALS; SPUTTERING; TESTING; WALL EFFECTS; U CODES; INTERATOMIC FORCES

Citation Formats

Rognlien, T. D., Beiersdorfer, Peter, Chernov, A., Frolov, T., Magee, E., Rudd, R., and Umansky, M. Plasma Interactions with Mixed Materials and Impurity Transport. United States: N. p., 2016. Web. doi:10.2172/1332472.
Rognlien, T. D., Beiersdorfer, Peter, Chernov, A., Frolov, T., Magee, E., Rudd, R., & Umansky, M. Plasma Interactions with Mixed Materials and Impurity Transport. United States. doi:10.2172/1332472.
Rognlien, T. D., Beiersdorfer, Peter, Chernov, A., Frolov, T., Magee, E., Rudd, R., and Umansky, M. Fri . "Plasma Interactions with Mixed Materials and Impurity Transport". United States. doi:10.2172/1332472. https://www.osti.gov/servlets/purl/1332472.
@article{osti_1332472,
title = {Plasma Interactions with Mixed Materials and Impurity Transport},
author = {Rognlien, T. D. and Beiersdorfer, Peter and Chernov, A. and Frolov, T. and Magee, E. and Rudd, R. and Umansky, M.},
abstractNote = {The project brings together three discipline areas at LLNL to develop advanced capability to predict the impact of plasma/material interactions (PMI) on metallic surfaces in magnetic fusion energy (MFE) devices. These areas are (1) modeling transport of wall impurity ions through the edge plasma to the core plasma, (2) construction of a laser blow-off (LBO) system for injecting precise amounts of metallic atoms into a tokamak plasma, and (3) material science analysis of fundamental processes that modify metallic surfaces during plasma bombardment. The focus is on tungsten (W), which is being used for the ITER divertor and in designs of future MFE devices. In area (1), we have worked with the University of California, San Diego (UCSD) on applications of the UEDGE/DUSTT coupled codes to predict the influx of impurity ions from W dust through the edge plasma, including periodic edge-plasma oscillations, and revived a parallel version of UEDGE to speed up these simulations. In addition, the impurity transport model in the 2D UEDGE code has been implemented into the 3D BOUT++ turbulence/transport code to allow fundamental analysis of the impact of strong plasma turbulence on the impurity transport. In area (2), construction and testing of the LBO injection system has been completed. The original plan to install the LBO on the National Spherical Torus Experiment Upgrade (NSTX-U) at Princeton and its use to validate the impurity transport simulations is delayed owing to NSTX-U being offline for substantial magnetic coil repair period. In area (3), an analytic model has been developed to explain the growth of W tendrils (or fuzz) observed for helium-containing plasmas. Molecular dynamics calculations of W sputtering by W and deuterium (D) ions shows that a spatial blending of interatomic potentials is needed to describe the near-surface and deeper regions of the material.},
doi = {10.2172/1332472},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2016},
month = {10}
}

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