Model of ELM suppression by RMPs in DIII-D

J. D. Callen; M. T. Beidler; N. M. Ferraro; C. C. Hegna; R. J. La Haye; R. Nazikian; C. Paz-Soldan

Model of ELM suppression by RMPs in DIII-D

J. D. Callen, M. T. Beidler, N. M. Ferraro, C. C. Hegna, R. J. La Haye, R. Nazikian, C. Paz-Soldan

Research output: Contribution to conference › Paper › peer-review

Abstract

Tokamak FMR theory [9] has been used to describe and quantify physical processes involved in various stages of RMP effects and an ELM crash response that lead to bifurcation into an ELM-suppressed state: 1) in the ELMing equilibrium, flow screening is strong with little magnetic reconnection; 2) the RMP at q = 8=2 penetrates via FMR induced by the ELM crash which locks the toroidal flow to the lab frame (like error field mode locking); 3) the ELM crash provides a 8/2 seed island (like NTMs) governed by the MRE; 4) then, if the total 8/2 RMP is large enough, the internal tearing-type (magnetic island) response and flow bifurcate; and 5) flutter transport significantly reduces pedestal top gradients, stabilizing P-B modes and thereby suppressing ELMs. This analysis is for discharge 158115 in DIII-D [1, 2]. More work is required to determine how universal this ELM-crash-induced ELM suppression scenario is and its potential utility in defining criteria for achieving ELM suppression with RMPs in ITER.

Original language	English
State	Published - 2016
Externally published	Yes
Event	43rd European Physical Society Conference on Plasma Physics, EPS 2016 - Leuven, Belgium Duration: Jul 4 2016 → Jul 8 2016

Conference

Conference	43rd European Physical Society Conference on Plasma Physics, EPS 2016
Country/Territory	Belgium
City	Leuven
Period	07/4/16 → 07/8/16

Funding

This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Award Numbers DE-FG02-92ER54139, DE-FG02-86ER53218, DE-AC02-09CH11466 and DE-FC02-04ER54698. References

Cite this

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title = "Model of ELM suppression by RMPs in DIII-D",

abstract = "Tokamak FMR theory [9] has been used to describe and quantify physical processes involved in various stages of RMP effects and an ELM crash response that lead to bifurcation into an ELM-suppressed state: 1) in the ELMing equilibrium, flow screening is strong with little magnetic reconnection; 2) the RMP at q = 8=2 penetrates via FMR induced by the ELM crash which locks the toroidal flow to the lab frame (like error field mode locking); 3) the ELM crash provides a 8/2 seed island (like NTMs) governed by the MRE; 4) then, if the total 8/2 RMP is large enough, the internal tearing-type (magnetic island) response and flow bifurcate; and 5) flutter transport significantly reduces pedestal top gradients, stabilizing P-B modes and thereby suppressing ELMs. This analysis is for discharge 158115 in DIII-D [1, 2]. More work is required to determine how universal this ELM-crash-induced ELM suppression scenario is and its potential utility in defining criteria for achieving ELM suppression with RMPs in ITER.",

author = "Callen, {J. D.} and Beidler, {M. T.} and Ferraro, {N. M.} and Hegna, {C. C.} and {La Haye}, {R. J.} and R. Nazikian and C. Paz-Soldan",

year = "2016",

language = "English",

note = "43rd European Physical Society Conference on Plasma Physics, EPS 2016 ; Conference date: 04-07-2016 Through 08-07-2016",

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TY - CONF

T1 - Model of ELM suppression by RMPs in DIII-D

AU - Callen, J. D.

AU - Beidler, M. T.

AU - Ferraro, N. M.

AU - Hegna, C. C.

AU - La Haye, R. J.

AU - Nazikian, R.

AU - Paz-Soldan, C.

PY - 2016

Y1 - 2016

N2 - Tokamak FMR theory [9] has been used to describe and quantify physical processes involved in various stages of RMP effects and an ELM crash response that lead to bifurcation into an ELM-suppressed state: 1) in the ELMing equilibrium, flow screening is strong with little magnetic reconnection; 2) the RMP at q = 8=2 penetrates via FMR induced by the ELM crash which locks the toroidal flow to the lab frame (like error field mode locking); 3) the ELM crash provides a 8/2 seed island (like NTMs) governed by the MRE; 4) then, if the total 8/2 RMP is large enough, the internal tearing-type (magnetic island) response and flow bifurcate; and 5) flutter transport significantly reduces pedestal top gradients, stabilizing P-B modes and thereby suppressing ELMs. This analysis is for discharge 158115 in DIII-D [1, 2]. More work is required to determine how universal this ELM-crash-induced ELM suppression scenario is and its potential utility in defining criteria for achieving ELM suppression with RMPs in ITER.

AB - Tokamak FMR theory [9] has been used to describe and quantify physical processes involved in various stages of RMP effects and an ELM crash response that lead to bifurcation into an ELM-suppressed state: 1) in the ELMing equilibrium, flow screening is strong with little magnetic reconnection; 2) the RMP at q = 8=2 penetrates via FMR induced by the ELM crash which locks the toroidal flow to the lab frame (like error field mode locking); 3) the ELM crash provides a 8/2 seed island (like NTMs) governed by the MRE; 4) then, if the total 8/2 RMP is large enough, the internal tearing-type (magnetic island) response and flow bifurcate; and 5) flutter transport significantly reduces pedestal top gradients, stabilizing P-B modes and thereby suppressing ELMs. This analysis is for discharge 158115 in DIII-D [1, 2]. More work is required to determine how universal this ELM-crash-induced ELM suppression scenario is and its potential utility in defining criteria for achieving ELM suppression with RMPs in ITER.

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M3 - Paper

AN - SCOPUS:85013872595

T2 - 43rd European Physical Society Conference on Plasma Physics, EPS 2016

Y2 - 4 July 2016 through 8 July 2016

ER -

Model of ELM suppression by RMPs in DIII-D

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Conference

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