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

Frerichs, H.; Schmitz, O.; Waters, I.; Canal, G. P.; Evans, T. E.; Feng, Y.; Soukhanovskii, V. A.

doi:10.1063/1.4954816

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

Journal Article · Wed Jun 01 00:00:00 EDT 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4954816· OSTI ID:1399721

Frerichs, H. ^[1]; Schmitz, O. ^[1]; ^[1]; Canal, G. P. ^[2]; ^[2]; Feng, Y. ^[3]; Soukhanovskii, V. A. ^[4]

Univ. of Wisconsin, Madison, WI (United States)
General Atomics, San Diego, CA (United States)
Max Planck Inst. for Plasma Physics, Greifswald (Germany)
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

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 (transients), but understanding their detailed impact is difficult due to their symmetry breaking nature. One approach for reducing steady state heat loads are 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 inter- action based on the NSTX-U setup. An overview of different divertor con gurations 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 is 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.

View Accepted Manuscript (DOE)

Research Organization:: Lawrence Livermore National Laboratory (LLNL), Livermore, CA

Sponsoring Organization:: USDOE

Grant/Contract Number:: AC52-07NA27344; FC02-04ER54698; SC0012315

OSTI ID:: 1399721

Alternate ID(s):: OSTI ID: 22598940
OSTI ID: 1259743

Report Number(s):: LLNL--JRNL-739361

Journal Information:: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 6 Vol. 23; ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

References (40)

Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U Frerichs, H.; Waters, I.; Schmitz, O. Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) https://doi.org/10.11578/1366498	dataset	January 2016
Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U Frerichs, H.; Waters, I.; Schmitz, O. Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) https://doi.org/10.11578/1562062	dataset	January 2016
3D Edge Modeling and Island Divertor Physics Feng, Y.; Sardei, F.; Kisslinger, J. Contributions to Plasma Physics, Vol. 44, Issue 13 https://doi.org/10.1002/ctpp.200410009	journal	April 2004
Homoclinic tangles, bifurcations and edge stochasticity in diverted tokamaks Evans, T. E.; Roeder, R. K. W.; Carter, J. A. Contributions to Plasma Physics, Vol. 44, Issue 13 https://doi.org/10.1002/ctpp.200410034	journal	April 2004
Recent Improvements in the EMC3-Eirene Code: Recent Improvements in the EMC3-Eirene Code Feng, Y.; Frerichs, H.; Kobayashi, M. Contributions to Plasma Physics, Vol. 54, Issue 4-6 https://doi.org/10.1002/ctpp.201410092	journal	June 2014
Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields Guckenheimer, John; Holmes, Philip Applied Mathematical Sciences https://doi.org/10.1007/978-1-4612-1140-2	book	January 1983
Influence of an ergodic magnetic limiter on the impurity content in a tokamak Engelhardt, W.; Feneberg, W. Journal of Nuclear Materials, Vol. 76-77 https://doi.org/10.1016/0022-3115(78)90198-8	journal	September 1978
Block-structured grids in Lagrangian 3D edge plasma transport simulations Frerichs, H.; Reiter, D.; Feng, Y. Computer Physics Communications, Vol. 181, Issue 1 https://doi.org/10.1016/j.cpc.2009.08.016	journal	January 2010
Stability and control of iterated non-linear transport solvers for fusion edge plasmas Frerichs, H.; Reiter, D. Computer Physics Communications, Vol. 188 https://doi.org/10.1016/j.cpc.2014.11.007	journal	March 2015
Edge stability and transport control with resonant magnetic perturbations in collisionless tokamak plasmas Evans, Todd E.; Moyer, Richard A.; Burrell, Keith H. Nature Physics, Vol. 2, Issue 6 https://doi.org/10.1038/nphys312	journal	May 2006
A simple highly accurate field-line mapping technique for three-dimensional Monte Carlo modeling of plasma edge transport Feng, Y.; Sardei, F.; Kisslinger, J. Physics of Plasmas, Vol. 12, Issue 5 https://doi.org/10.1063/1.1888959	journal	May 2005
Geometrical properties of a “snowflake” divertor Ryutov, D. D. Physics of Plasmas, Vol. 14, Issue 6 https://doi.org/10.1063/1.2738399	journal	June 2007
On heat loading, novel divertors, and fusion reactors Kotschenreuther, M.; Valanju, P. M.; Mahajan, S. M. Physics of Plasmas, Vol. 14, Issue 7 https://doi.org/10.1063/1.2739422	journal	July 2007
The magnetic field structure of a snowflake divertor Ryutov, D. D.; Cohen, R. H.; Rognlien, T. D. Physics of Plasmas, Vol. 15, Issue 9 https://doi.org/10.1063/1.2967900	journal	September 2008
Super-X divertors and high power density fusion devices Valanju, P. M.; Kotschenreuther, M.; Mahajan, S. M. Physics of Plasmas, Vol. 16, Issue 5 https://doi.org/10.1063/1.3110984	journal	May 2009
Importance of plasma response to nonaxisymmetric perturbations in tokamaks Park, Jong-kyu; Boozer, Allen H.; Menard, Jonathan E. Physics of Plasmas, Vol. 16, Issue 5 https://doi.org/10.1063/1.3122862	journal	May 2009
Effect of nonaxisymmetric magnetic perturbations on divertor heat and particle flux profiles in National Spherical Torus Experiment Ahn, J-W.; Maingi, R.; Canik, J. M. Physics of Plasmas, Vol. 18, Issue 5 https://doi.org/10.1063/1.3574522	journal	May 2011
Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake Kotschenreuther, Mike; Valanju, Prashant; Covele, Brent Physics of Plasmas, Vol. 20, Issue 10 https://doi.org/10.1063/1.4824735	journal	October 2013
Comment on “Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake” [Phys. Plasmas 20 , 102507 (2013)] Ryutov, D. D.; Cohen, R. H.; Rognlien, T. D. Physics of Plasmas, Vol. 21, Issue 5 https://doi.org/10.1063/1.4873404	journal	May 2014
Response to “Comment on ‘Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake’ ” [Phys. Plasmas 21 , 054701 (2014)] Kotschenreuther, Mike; Valanju, Prashant; Covele, Brent Physics of Plasmas, Vol. 21, Issue 5 https://doi.org/10.1063/1.4873405	journal	May 2014
The pattern of parallel edge plasma flows due to pressure gradients, recycling, and resonant magnetic perturbations in DIII-D Frerichs, H.; Schmitz, O.; Evans, T. Physics of Plasmas, Vol. 22, Issue 7 https://doi.org/10.1063/1.4926524	journal	July 2015
A helical magnetic limiter for boundary layer control in large tokamaks Feneberg, W.; Wolf, G. H. Nuclear Fusion, Vol. 21, Issue 6 https://doi.org/10.1088/0029-5515/21/6/006	journal	June 1981
Three-dimensional edge transport simulations for DIII-D plasmas with resonant magnetic perturbations Frerichs, H.; Reiter, D.; Schmitz, O. Nuclear Fusion, Vol. 50, Issue 3 https://doi.org/10.1088/0029-5515/50/3/034004	journal	February 2010
Implementation of the 3D edge plasma code EMC3-EIRENE on NSTX Lore, J. D.; Canik, J. M.; Feng, Y. Nuclear Fusion, Vol. 52, Issue 5 https://doi.org/10.1088/0029-5515/52/5/054012	journal	May 2012
First EMC3-Eirene simulations of the impact of the edge magnetic perturbations at ASDEX Upgrade compared with the experiment Lunt, T.; Feng, Y.; Bernert, M. Nuclear Fusion, Vol. 52, Issue 5 https://doi.org/10.1088/0029-5515/52/5/054013	journal	May 2012
Overview of the physics and engineering design of NSTX upgrade Menard, J. E.; Gerhardt, S.; Bell, M. Nuclear Fusion, Vol. 52, Issue 8 https://doi.org/10.1088/0029-5515/52/8/083015	journal	July 2012
3D vacuum magnetic field modelling of the ITER ELM control coil during standard operating scenarios Evans, T. E.; Orlov, D. M.; Wingen, A. Nuclear Fusion, Vol. 53, Issue 9 https://doi.org/10.1088/0029-5515/53/9/093029	journal	August 2013
Formation of a three-dimensional plasma boundary after decay of the plasma response to resonant magnetic perturbation fields Schmitz, O.; Evans, T. E.; Fenstermacher, M. E. Nuclear Fusion, Vol. 54, Issue 1 https://doi.org/10.1088/0029-5515/54/1/012001	journal	December 2013
Progress on the application of ELM control schemes to ITER scenarios from the non-active phase to DT operation Loarte, A.; Huijsmans, G.; Futatani, S. Nuclear Fusion, Vol. 54, Issue 3 https://doi.org/10.1088/0029-5515/54/3/033007	journal	February 2014
Method for comparison of tokamak divertor strike point data with magnetic perturbation models Cahyna, P.; Peterka, M.; Nardon, E. Nuclear Fusion, Vol. 54, Issue 6 https://doi.org/10.1088/0029-5515/54/6/064002	journal	May 2014
Three-dimensional modeling of plasma edge transport and divertor fluxes during application of resonant magnetic perturbations on ITER Schmitz, O.; Becoulet, M.; Cahyna, P. Nuclear Fusion, Vol. 56, Issue 6 https://doi.org/10.1088/0029-5515/56/6/066008	journal	May 2016
Aspects of three dimensional transport for ELM control experiments in ITER-similar shape plasmas at low collisionality in DIII-D Schmitz, O.; Evans, T. E.; Fenstermacher, M. E. Plasma Physics and Controlled Fusion, Vol. 50, Issue 12 https://doi.org/10.1088/0741-3335/50/12/124029	journal	November 2008
Local properties of the magnetic field in a snowflake divertor Ryutov, D. D.; Makowski, M. A.; Umansky, M. V. Plasma Physics and Controlled Fusion, Vol. 52, Issue 10 https://doi.org/10.1088/0741-3335/52/10/105001	journal	August 2010
First EMC3-Eirene simulations of the TCV snowflake divertor Lunt, T.; Canal, G. P.; Feng, Y. Plasma Physics and Controlled Fusion, Vol. 56, Issue 3 https://doi.org/10.1088/0741-3335/56/3/035009	journal	February 2014
Resonant magnetic perturbations of edge-plasmas in toroidal confinement devices Evans, T. E. Plasma Physics and Controlled Fusion, Vol. 57, Issue 12 https://doi.org/10.1088/0741-3335/57/12/123001	journal	November 2015
Experimental signatures of homoclinic tangles in poloidally diverted tokamaks Evans, T. E.; Roeder, R. K. W.; Carter, J. A. Journal of Physics: Conference Series, Vol. 7 https://doi.org/10.1088/1742-6596/7/1/015	journal	January 2005
On Demand Triggering of Edge Localized Instabilities Using External Nonaxisymmetric Magnetic Perturbations in Toroidal Plasmas Canik, J. M.; Maingi, R.; Evans, T. E. Physical Review Letters, Vol. 104, Issue 4 https://doi.org/10.1103/PhysRevLett.104.045001	journal	January 2010
First Observation of Edge Localized Modes Mitigation with Resonant and Nonresonant Magnetic Perturbations in ASDEX Upgrade Suttrop, W.; Eich, T.; Fuchs, J. C. Physical Review Letters, Vol. 106, Issue 22 https://doi.org/10.1103/PhysRevLett.106.225004	journal	June 2011
Active Control of Type-I Edge-Localized Modes with n = 1 Perturbation Fields in the JET Tokamak Liang, Y.; Koslowski, H. R.; Thomas, P. R. Physical Review Letters, Vol. 98, Issue 26 https://doi.org/10.1103/PhysRevLett.98.265004	journal	June 2007
Magnetic Geometry and Physics of Advanced Divertors: The X-Divertor and the Snowflake Kotschenreuther, Mike; Valanju, Prashant; Covele, Brent arXiv https://doi.org/10.48550/arxiv.1309.5289	text	January 2013

Cited By (3)

Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U Frerichs, H.; Waters, I.; Schmitz, O. Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) https://doi.org/10.11578/1562062	dataset	January 2016
Field aligned flows driven by neutral puffing at MAST Waters, I.; Frerichs, H.; Silburn, S. Nuclear Fusion, Vol. 58, Issue 6 https://doi.org/10.1088/1741-4326/aab7ad	journal	April 2018
Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U Frerichs, H.; Waters, I.; Schmitz, O. Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) https://doi.org/10.11578/1366498	dataset	January 2016