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Title: A simplified lithium vapor box divertor

Abstract

A detached divertor plasma is predicted to be necessary to mitigate the heat fluxes and ion energy, and so sputtering, at the divertor plate of a fusion power plant. It has proven difficult in current experiments, however, to prevent the detachment front, once formed, from running up to the main plasma resulting in deterioration of pedestal performance. The lithium vapor box divertor localizes a dense cloud of lithium vapor away from the main plasma, in order to induce detachment at a stable, distant location. The vapor localization is created by local evaporation and nearby condensation, a configuration inaccessible for non-condensing seed impurities. This paper provides simulations of lithium vapor flow using the SPARTA direct simulation Monte Carlo (DSMC) code, in which the lithium vapor dynamics are governed by Li–Li collisions that should dominate in regions with little plasma. Inertia is included in this code, permitting the formation of shocks. The plasma model implemented in SPARTA is based on UEDGE results for the location of ionization and recombination. We find that a simplified lithium vapor box configuration, without baffles, provides robust stabilization of the detachment front and acceptable lithium vapor flow to the main chamber. Lithium is evaporated from a capillarymore » porous surface on the private-flux side of the divertor, distant from the main plasma, and is condensed on the other side walls of the divertor chamber. The condensed lithium flows back to the evaporator through 2 cm internal diameter pipes. The capillary pressure differential at the surface of the evaporator is capable of overcoming MHD back-force in the piping, with a great deal of margin if a sandwich flow channel insert is implemented. Very little lithium should be accumulated on the first wall of the main chamber if it is maintained at 600 °C, as expected for a power-producing fusion system.« less

Authors:
ORCiD logo [1]; ORCiD logo [1];  [1];  [2];  [2]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1558761
Grant/Contract Number:  
AC02-09CH11466; AC52-07NA27344
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 59; Journal Issue: 8; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; divertor; lithium; DSMC; detachment; lithium vapor box; FEC 2018; FNSF

Citation Formats

Emdee, E. D., Goldston, R. J., Schwartz, J. A., Rensink, M., and Rognlien, T. D. A simplified lithium vapor box divertor. United States: N. p., 2019. Web. doi:10.1088/1741-4326/ab2825.
Emdee, E. D., Goldston, R. J., Schwartz, J. A., Rensink, M., & Rognlien, T. D. A simplified lithium vapor box divertor. United States. doi:10.1088/1741-4326/ab2825.
Emdee, E. D., Goldston, R. J., Schwartz, J. A., Rensink, M., and Rognlien, T. D. Fri . "A simplified lithium vapor box divertor". United States. doi:10.1088/1741-4326/ab2825.
@article{osti_1558761,
title = {A simplified lithium vapor box divertor},
author = {Emdee, E. D. and Goldston, R. J. and Schwartz, J. A. and Rensink, M. and Rognlien, T. D.},
abstractNote = {A detached divertor plasma is predicted to be necessary to mitigate the heat fluxes and ion energy, and so sputtering, at the divertor plate of a fusion power plant. It has proven difficult in current experiments, however, to prevent the detachment front, once formed, from running up to the main plasma resulting in deterioration of pedestal performance. The lithium vapor box divertor localizes a dense cloud of lithium vapor away from the main plasma, in order to induce detachment at a stable, distant location. The vapor localization is created by local evaporation and nearby condensation, a configuration inaccessible for non-condensing seed impurities. This paper provides simulations of lithium vapor flow using the SPARTA direct simulation Monte Carlo (DSMC) code, in which the lithium vapor dynamics are governed by Li–Li collisions that should dominate in regions with little plasma. Inertia is included in this code, permitting the formation of shocks. The plasma model implemented in SPARTA is based on UEDGE results for the location of ionization and recombination. We find that a simplified lithium vapor box configuration, without baffles, provides robust stabilization of the detachment front and acceptable lithium vapor flow to the main chamber. Lithium is evaporated from a capillary porous surface on the private-flux side of the divertor, distant from the main plasma, and is condensed on the other side walls of the divertor chamber. The condensed lithium flows back to the evaporator through 2 cm internal diameter pipes. The capillary pressure differential at the surface of the evaporator is capable of overcoming MHD back-force in the piping, with a great deal of margin if a sandwich flow channel insert is implemented. Very little lithium should be accumulated on the first wall of the main chamber if it is maintained at 600 °C, as expected for a power-producing fusion system.},
doi = {10.1088/1741-4326/ab2825},
journal = {Nuclear Fusion},
number = 8,
volume = 59,
place = {United States},
year = {2019},
month = {7}
}

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Works referenced in this record:

Theoretical aspects and practical implications of the heuristic drift SOL model
journal, August 2015


A new experimental classification of divertor detachment in ASDEX Upgrade
journal, November 2013


Recent advances towards a lithium vapor box divertor
journal, August 2017


Study of lithium vapor flow in a detached divertor using DSMC code
journal, May 2019


Simulations of a high-density, highly-radiating lithium divertor
journal, January 2019


The Fusion Nuclear Science Facility, the Critical Step in the Pathway to Fusion Energy
journal, September 2015

  • Kessel, C. E.; Blanchard, J. P.; Davis, A.
  • Fusion Science and Technology, Vol. 68, Issue 2
  • DOI: 10.13182/FST14-953

A distillation column for hydrogen isotope removal from liquid lithium
journal, October 2018


Growth and decomposition of lithium and lithium hydride on nickel
journal, April 2006


Conceptual design of a pre-loaded liquid lithium divertor target for NSTX-U
journal, November 2016