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Title: Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U

Abstract

The control of divertor heat loads—both steady state and transient—remains a key challenge for the successful operation of ITER and FNSF. Magnetic perturbations provide a promising technique to control ELMs (Edge Localized Modes) (transients), but understanding their detailed impact is difficult due to their symmetry breaking nature. One approach for reducing steady state heat loads is so called “advanced divertors” which aim at optimizing the magnetic field configuration: the snowflake and the (super-)X-divertor. It is likely that both concepts—magnetic perturbations and advanced divertors—will have to work together, and we explore their interaction based on the NSTX-U setup. An overview of different divertor configurations under the impact of magnetic perturbations is presented, and the resulting impact on plasma edge transport is investigated with the EMC3-EIRENE code. Variations in size of the magnetic footprint of the perturbed separatrix are found, which are related to the level of flux expansion on the divertor target. Non-axisymmetric peaking of the heat flux related to the perturbed separatrix is found at the outer strike point, but only in locations where flux expansion is not too large.

Authors:
; ;  [1]; ;  [2];  [3];  [4]
  1. Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)
  2. General Atomics, San Diego, California 92186 (United States)
  3. Max-Planck Institute for Plasma Physics, Greifswald (Germany)
  4. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
Publication Date:
OSTI Identifier:
22598940
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 23; Journal Issue: 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AXIAL SYMMETRY; CONFIGURATION; CONTROL; DISTURBANCES; DIVERTORS; EDGE LOCALIZED MODES; EXPANSION; EXPLORATION; HEAT; HEAT FLUX; HEATING LOAD; ITER TOKAMAK; MAGNETIC FIELD CONFIGURATIONS; MAGNETIC FIELDS; NSTX DEVICE; OPTIMIZATION; PERTURBATION THEORY; PLASMA; STEADY-STATE CONDITIONS; SYMMETRY BREAKING

Citation Formats

Frerichs, H., Schmitz, O., Waters, I., Canal, G. P., Evans, T. E., Feng, Y., and Soukhanovskii, V. A.. Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U. United States: N. p., 2016. Web. doi:10.1063/1.4954816.
Frerichs, H., Schmitz, O., Waters, I., Canal, G. P., Evans, T. E., Feng, Y., & Soukhanovskii, V. A.. Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U. United States. doi:10.1063/1.4954816.
Frerichs, H., Schmitz, O., Waters, I., Canal, G. P., Evans, T. E., Feng, Y., and Soukhanovskii, V. A.. Wed . "Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U". United States. doi:10.1063/1.4954816.
@article{osti_22598940,
title = {Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U},
author = {Frerichs, H. and Schmitz, O. and Waters, I. and Canal, G. P. and Evans, T. E. and Feng, Y. and Soukhanovskii, V. A.},
abstractNote = {The control of divertor heat loads—both steady state and transient—remains a key challenge for the successful operation of ITER and FNSF. Magnetic perturbations provide a promising technique to control ELMs (Edge Localized Modes) (transients), but understanding their detailed impact is difficult due to their symmetry breaking nature. One approach for reducing steady state heat loads is so called “advanced divertors” which aim at optimizing the magnetic field configuration: the snowflake and the (super-)X-divertor. It is likely that both concepts—magnetic perturbations and advanced divertors—will have to work together, and we explore their interaction based on the NSTX-U setup. An overview of different divertor configurations under the impact of magnetic perturbations is presented, and the resulting impact on plasma edge transport is investigated with the EMC3-EIRENE code. Variations in size of the magnetic footprint of the perturbed separatrix are found, which are related to the level of flux expansion on the divertor target. Non-axisymmetric peaking of the heat flux related to the perturbed separatrix is found at the outer strike point, but only in locations where flux expansion is not too large.},
doi = {10.1063/1.4954816},
journal = {Physics of Plasmas},
number = 6,
volume = 23,
place = {United States},
year = {Wed Jun 15 00:00:00 EDT 2016},
month = {Wed Jun 15 00:00:00 EDT 2016}
}