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Title: Global modeling of wall material migration following boronization in NSTX-U

Journal Article · · Nuclear Materials and Energy
 [1];  [2];  [2];  [3];  [4];  [4];  [5]
  1. Univ. of Tennessee, Knoxville, TN (United States)
  2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  3. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  4. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  5. Max Planck Inst. for Plasmaphysik, Garching (Germany)

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. In conclusion, 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.

Research Organization:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
AC02-09CH11466; AC52-07NA27344
OSTI ID:
1564392
Alternate ID(s):
OSTI ID: 1567998; OSTI ID: 1580591
Report Number(s):
LLNL-JRNL-791935; TRN: US2102325
Journal Information:
Nuclear Materials and Energy, Vol. 19, Issue C; ISSN 2352-1791
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

References (17)

Wall conditioning in fusion devices and its influence on plasma performance journal September 1996
Effect of boronization on ohmic plasmas in NSTX journal March 2002
Advances in boronization on NSTX-Upgrade journal August 2017
An integrated model of impurity migration and wall composition dynamics for tokamaks journal August 2011
WALLDYN simulations of global impurity migration in JET and extrapolations to ITER journal April 2015
Quantitative modeling of fuel retention in the JET-C and JET-ILW wall configurations by WallDYN and predictions for ITER journal August 2015
Chemical erosion of carbon based materials in fusion devices journal March 1999
The EIRENE and B2-EIRENE Codes journal February 2005
Interpretive modeling of simple-as-possible-plasma discharges on DIII-D using the OEDGE code journal March 2003
Pulse-by-pulse measurements of dynamic retention and deposition in NSTX journal June 2007
Modelling of tokamak glow discharge cleaning I: physical principles journal December 2014
Modelling of tokamak glow discharge cleaning II: comparison with experiment and application to ITER journal December 2014
Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade journal February 2018
Initial studies of plasma facing component surface conditioning in the national spherical tokamak experiment upgrade with the materials analysis particle probe journal August 2017
Design assessment of tungsten as an upper panel plasma facing material in ITER journal July 2013
Measurements and 2-D modeling of recycling and edge transport in discharges with lithium-coated PFCs in NSTX journal August 2011
A dual wavelength imaging system for plasma-surface interaction studies on the National Spherical Torus Experiment Upgrade journal December 2015

Cited By (1)

Fusion applications for lithium: wall conditioning in magnetic confinement devices journal October 2019

Figures / Tables (7)