U.S. Department of EnergyOffice of Scientific and Technical Information
Global modeling of wall material migration following boronization in NSTX-U
Abstract
Boronization is commonly utilized in tokamaks to suppress intrinsic impurities, most notably oxygen from residual water vapor. However, this is a temporary solution, as oxygen levels typically return to pre-boronization levels following repeated plasma exposure. The global impurity migration model WallDYN has been applied to the post-boronization surface impurity evolution in NSTX-U. A "Thin Film Model" has been incorporated into WallDYN to handle spatially inhomogeneous conditioning films of varying thicknesses, together with an empirical boron conditioning model for the NSTX-U glow discharge boronization process. The model qualitatively reproduces the spatial distribution of boron in the NSTX-U vessel, the spatially-resolved divertor emission pattern, and the increase in oxygen levels following boronization. The simulations suggest that oxygen is primarily sourced from wall locations without heavy plasma flux or significant boron deposition, namely the lower and upper passive plates and the lower private flux zone.
- Authors:
-
- OSTI
- Publication Date:
- DOE Contract Number:
- AC02-09CH11466
- Research Org.:
- Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
- Sponsoring Org.:
- U. S. Department of Energy
- Subject:
- Integrated modeling
- OSTI Identifier:
- 1562080
- DOI:
- https://doi.org/10.11578/1562080
Citation Formats
Nichols, J H, Jaworski, M A, Skinner, C H, Bedoya, F, Scotti, F, Soukhanovskii, V A, and Schmid, K. Global modeling of wall material migration following boronization in NSTX-U. United States: N. p., 2019.
Web. doi:10.11578/1562080.
Nichols, J H, Jaworski, M A, Skinner, C H, Bedoya, F, Scotti, F, Soukhanovskii, V A, & Schmid, K. Global modeling of wall material migration following boronization in NSTX-U. United States. doi:https://doi.org/10.11578/1562080
Nichols, J H, Jaworski, M A, Skinner, C H, Bedoya, F, Scotti, F, Soukhanovskii, V A, and Schmid, K. 2019.
"Global modeling of wall material migration following boronization in NSTX-U". United States. doi:https://doi.org/10.11578/1562080. https://www.osti.gov/servlets/purl/1562080. Pub date:Fri Mar 01 04:00:00 UTC 2019
@article{osti_1562080,
title = {Global modeling of wall material migration following boronization in NSTX-U},
author = {Nichols, J H and Jaworski, M A and Skinner, C H and Bedoya, F and Scotti, F and Soukhanovskii, V A and Schmid, K},
abstractNote = {Boronization is commonly utilized in tokamaks to suppress intrinsic impurities, most notably oxygen from residual water vapor. However, this is a temporary solution, as oxygen levels typically return to pre-boronization levels following repeated plasma exposure. The global impurity migration model WallDYN has been applied to the post-boronization surface impurity evolution in NSTX-U. A "Thin Film Model" has been incorporated into WallDYN to handle spatially inhomogeneous conditioning films of varying thicknesses, together with an empirical boron conditioning model for the NSTX-U glow discharge boronization process. The model qualitatively reproduces the spatial distribution of boron in the NSTX-U vessel, the spatially-resolved divertor emission pattern, and the increase in oxygen levels following boronization. The simulations suggest that oxygen is primarily sourced from wall locations without heavy plasma flux or significant boron deposition, namely the lower and upper passive plates and the lower private flux zone.},
doi = {10.11578/1562080},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Mar 01 04:00:00 UTC 2019},
month = {Fri Mar 01 04:00:00 UTC 2019}
}