skip to main content

DOE PAGESDOE PAGES

Title: Attainment of a stable, fully detached plasma state in innovative divertor configurations

A computational study of long-legged tokamak divertor configurations is performed with the edge transport code UEDGE. Several divertor configurations are considered, with radially or vertically extended, tightly baffled, outer divertor legs and with or without a secondary X-point in the divertor leg volume. For otherwise identical conditions, a scan of the input power from the core plasma is performed. As the power is reduced to a threshold value, the plasma in the outer leg transitions to a fully detached state, which defines the upper limit on the power for detached divertor operation. Reducing the power further results in the detachment front shifting upstream but remains stable. At low power, the detachment front eventually moves all the way to the primary X-point, which is usually associated with degradation of the core plasma, and this defines the lower limit on the power for the detached divertor operation. For the studied parameters, for long-legged divertors, the detached operation window is quite large, in particular, for the X-point target configuration using a secondary X-point in the divertor leg volume, allowing a factor of 5–10 variations in the input power. For the same parameters, for the standard divertor configuration, the detached operation window is verymore » small or even non-existent. In conclusion, the present modeling results suggest the possibility of stable fully detached divertor operation for a tokamak with tightly baffled extended divertor legs.« less
Authors:
 [1] ;  [2] ;  [2] ;  [1] ;  [1] ; ORCiD logo [2] ;  [2]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  2. MIT Plasma Science and Fusion Center, Cambridge, MA (United States)
Publication Date:
Report Number(s):
LLNL-JRNL-712618
Journal ID: ISSN 1070-664X; 850966
Grant/Contract Number:
AC52-07NA27344
Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 5; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
OSTI Identifier:
1461739
Alternate Identifier(s):
OSTI ID: 1373961

Umansky, M. V., LaBombard, B., Brunner, D., Rensink, M. E., Rognlien, T. D., Terry, J. L., and Whyte, D. G.. Attainment of a stable, fully detached plasma state in innovative divertor configurations. United States: N. p., Web. doi:10.1063/1.4979193.
Umansky, M. V., LaBombard, B., Brunner, D., Rensink, M. E., Rognlien, T. D., Terry, J. L., & Whyte, D. G.. Attainment of a stable, fully detached plasma state in innovative divertor configurations. United States. doi:10.1063/1.4979193.
Umansky, M. V., LaBombard, B., Brunner, D., Rensink, M. E., Rognlien, T. D., Terry, J. L., and Whyte, D. G.. 2017. "Attainment of a stable, fully detached plasma state in innovative divertor configurations". United States. doi:10.1063/1.4979193. https://www.osti.gov/servlets/purl/1461739.
@article{osti_1461739,
title = {Attainment of a stable, fully detached plasma state in innovative divertor configurations},
author = {Umansky, M. V. and LaBombard, B. and Brunner, D. and Rensink, M. E. and Rognlien, T. D. and Terry, J. L. and Whyte, D. G.},
abstractNote = {A computational study of long-legged tokamak divertor configurations is performed with the edge transport code UEDGE. Several divertor configurations are considered, with radially or vertically extended, tightly baffled, outer divertor legs and with or without a secondary X-point in the divertor leg volume. For otherwise identical conditions, a scan of the input power from the core plasma is performed. As the power is reduced to a threshold value, the plasma in the outer leg transitions to a fully detached state, which defines the upper limit on the power for detached divertor operation. Reducing the power further results in the detachment front shifting upstream but remains stable. At low power, the detachment front eventually moves all the way to the primary X-point, which is usually associated with degradation of the core plasma, and this defines the lower limit on the power for the detached divertor operation. For the studied parameters, for long-legged divertors, the detached operation window is quite large, in particular, for the X-point target configuration using a secondary X-point in the divertor leg volume, allowing a factor of 5–10 variations in the input power. For the same parameters, for the standard divertor configuration, the detached operation window is very small or even non-existent. In conclusion, the present modeling results suggest the possibility of stable fully detached divertor operation for a tokamak with tightly baffled extended divertor legs.},
doi = {10.1063/1.4979193},
journal = {Physics of Plasmas},
number = 5,
volume = 24,
place = {United States},
year = {2017},
month = {3}
}