Inter-ELM evolution of the edge current density in JET-ILW type i ELMy H-mode plasmas

Laszlo Horvath; C.F. Maggi; F.J. Casson; V. Parail; L. Frassinetti; F. Koechl; S. Saarelma; M.G. Dunne; K.J. Gibson; Leena Aho-Mantila; Markus Airila; Antti Hakola; Aaro Järvinen; Juuso Karhunen; Seppo Koivuranta; Aki Lahtinen; Jari Likonen; Antti Salmi; Paula Sirén; Tuomas Tala; JET Contributors

doi:10.1088/1361-6587/aac7a9

Inter-ELM evolution of the edge current density in JET-ILW type i ELMy H-mode plasmas

Laszlo Horvath^*
, C.F. Maggi
, F.J. Casson
, V. Parail
, L. Frassinetti
, F. Koechl
, S. Saarelma
, M.G. Dunne
, K.J. Gibson
, Leena Aho-Mantila
, Markus Airila
, Antti Hakola
, Aaro Järvinen
, Juuso Karhunen
, Seppo Koivuranta
, Aki Lahtinen
, Jari Likonen
, Antti Salmi
, Paula Sirén
, Tuomas Tala

JET Contributors

^*Corresponding author for this work

University of York
Culham Science Centre
KTH Royal Institute of Technology
Max-Planck-Institut für Plasmaphysik (IPP)
Forschungszentrum Jülich GmbH (FZJ)
Institute for Plasma Research
Universidade de Lisboa
Queen's University Belfast
University of Helsinki
Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA)
National Institutes for Quantum Science and Technology (QST)
University of Naples Federico II
National University of Distance Education
National Research Council (CNR)
ITER Organization
Petersburg Nuclear Physics Institute
Parthenope University of Naples
National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA)
Troitsk Institute for Innovation and Fusion Research
Uppsala University
National Institute for Cryogenics and Isotopic Technology
University of Catania
Fusion for Energy (F4E)
Aalto University
Seoul National University
Institute of Plasma Physics (ASIPP CAS)
Chalmers University of Technology

Research output: Contribution to journal › Article › Scientific › peer-review

7 Citations (Scopus)

Abstract

Recent studies (Maggi et al 2015 Nucl. Fusion 55 113031; Maggi et al 2017 Nucl. Fusion 57 116012) have shown that on JET with the Be/W ITER-like wall (JET-ILW) in high β discharges with high D₂ gas rates, the inter-ELM temperature pedestal growth is saturated half way through the ELM cycle, leading to plasmas with reduced confinement, and that the linear MHD stability of these pedestals is inconsistent with the peeling-ballooning paradigm (Snyder et al 2002 Phys. Plasmas 9 2037-43; Wilson et al 2002 Phys. Plasmas 9 1277-86). In this paper, the inter-ELM evolution of the edge current density is investigated in a wide range of type I ELMy H-modes on JET-ILW. It is found that in discharges at a low gas rate, the peak edge bootstrap current continuously increases until the ELM crashes, while it saturates during the ELM cycle at high gas rates. The effect of current diffusion on the build-up of the edge current inter-ELM is assessed by simulating the Ohmic current contribution with the JETTO transport code. The simulations indicate that current diffusion contributes little to the time evolution of the total edge current in the second half of the ELM cycle and the total current is dominated by the bootstrap current. Therefore, current diffusion does not explain why JET-ILW type I ELMy pedestals at a high gas rate and high β_N are found to be stable to peeling-ballooning modes.

Original language	English
Article number	085003
Journal	Plasma Physics and Controlled Fusion
Volume	60
Issue number	8
DOIs	https://doi.org/10.1088/1361-6587/aac7a9
Publication status	Published - 13 Jun 2018
MoE publication type	A1 Journal article-refereed

Funding

This work was supported by the Engineering and Physical Sciences Research Council (EP/ L01663X/1). This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under grant agreement No 633053.

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

Keywords

bootstrap current
current diffusion
edge current
ELMs
H-mode
JET-ILW
pedestal

Access to Document

10.1088/1361-6587/aac7a9

Cite this

Horvath, L., Maggi, C. F., Casson, F. J., Parail, V., Frassinetti, L., Koechl, F., Saarelma, S., Dunne, M. G., Gibson, K. J., Aho-Mantila, L., Airila, M., Hakola, A., Järvinen, A., Karhunen, J., Koivuranta, S., Lahtinen, A., Likonen, J., Salmi, A., Sirén, P., ... JET Contributors (2018). Inter-ELM evolution of the edge current density in JET-ILW type i ELMy H-mode plasmas. Plasma Physics and Controlled Fusion, 60(8), Article 085003. https://doi.org/10.1088/1361-6587/aac7a9

@article{feef9624f1d8425eaba9610654f3b410,

title = "Inter-ELM evolution of the edge current density in JET-ILW type i ELMy H-mode plasmas",

abstract = "Recent studies (Maggi et al 2015 Nucl. Fusion 55 113031; Maggi et al 2017 Nucl. Fusion 57 116012) have shown that on JET with the Be/W ITER-like wall (JET-ILW) in high β discharges with high D2 gas rates, the inter-ELM temperature pedestal growth is saturated half way through the ELM cycle, leading to plasmas with reduced confinement, and that the linear MHD stability of these pedestals is inconsistent with the peeling-ballooning paradigm (Snyder et al 2002 Phys. Plasmas 9 2037-43; Wilson et al 2002 Phys. Plasmas 9 1277-86). In this paper, the inter-ELM evolution of the edge current density is investigated in a wide range of type I ELMy H-modes on JET-ILW. It is found that in discharges at a low gas rate, the peak edge bootstrap current continuously increases until the ELM crashes, while it saturates during the ELM cycle at high gas rates. The effect of current diffusion on the build-up of the edge current inter-ELM is assessed by simulating the Ohmic current contribution with the JETTO transport code. The simulations indicate that current diffusion contributes little to the time evolution of the total edge current in the second half of the ELM cycle and the total current is dominated by the bootstrap current. Therefore, current diffusion does not explain why JET-ILW type I ELMy pedestals at a high gas rate and high βN are found to be stable to peeling-ballooning modes.",

keywords = "bootstrap current, current diffusion, edge current, ELMs, H-mode, JET-ILW, pedestal",

author = "Laszlo Horvath and C.F. Maggi and F.J. Casson and V. Parail and L. Frassinetti and F. Koechl and S. Saarelma and M.G. Dunne and K.J. Gibson and X. Litaudon and S. Abduallev and M. Abhangi and P. Abreu and M. Afzal and Aggarwal, \{K. M.\} and T. Ahlgren and Ahn, \{J. H.\} and Leena Aho-Mantila and N. Aiba and Markus Airila and R. Albanese and V. Aldred and D. Alegre and E. Alessi and P. Aleynikov and A. Alfier and A. Alkseev and M. Allinson and B. Alper and E. Alves and G. Ambrosino and R. Ambrosino and L. Amicucci and V. Amosov and Sund{\'e}n, \{E. Andersson\} and M. Angelone and M. Anghel and C. Angioni and L. Appel and C. Appelbee and P. Arena and M. Ariola and H. Arnichand and S. Arshad and Antti Hakola and Aaro J{\"a}rvinen and Juuso Karhunen and H.T. Kim and H.S. Kim and Seppo Koivuranta and Aki Lahtinen and Jari Likonen and Y. Liu and T. Makkonen and H. Nordman and Antti Salmi and M.I.K. Santala and Paula Sir{\'e}n and Tuomas Tala and \{JET Contributors\}",

note = "Publisher Copyright: {\textcopyright} 2018 York Plasma Institute.",

year = "2018",

month = jun,

day = "13",

doi = "10.1088/1361-6587/aac7a9",

language = "English",

volume = "60",

journal = "Plasma Physics and Controlled Fusion",

issn = "0741-3335",

publisher = "Institute of Physics IOP",

number = "8",

}

Horvath, L, Maggi, CF, Casson, FJ, Parail, V, Frassinetti, L, Koechl, F, Saarelma, S, Dunne, MG, Gibson, KJ, Aho-Mantila, L , Airila, M , Hakola, A , Järvinen, A , Karhunen, J, Koivuranta, S, Lahtinen, A, Likonen, J , Salmi, A, Sirén, P, Tala, T & JET Contributors 2018, 'Inter-ELM evolution of the edge current density in JET-ILW type i ELMy H-mode plasmas', Plasma Physics and Controlled Fusion, vol. 60, no. 8, 085003. https://doi.org/10.1088/1361-6587/aac7a9

TY - JOUR

T1 - Inter-ELM evolution of the edge current density in JET-ILW type i ELMy H-mode plasmas

AU - Horvath, Laszlo

AU - Maggi, C.F.

AU - Casson, F.J.

AU - Parail, V.

AU - Frassinetti, L.

AU - Koechl, F.

AU - Saarelma, S.

AU - Dunne, M.G.

AU - Gibson, K.J.

AU - Litaudon, X.

AU - Abduallev, S.

AU - Abhangi, M.

AU - Abreu, P.

AU - Afzal, M.

AU - Aggarwal, K. M.

AU - Ahlgren, T.

AU - Ahn, J. H.

AU - Aho-Mantila, Leena

AU - Aiba, N.

AU - Airila, Markus

AU - Albanese, R.

AU - Aldred, V.

AU - Alegre, D.

AU - Alessi, E.

AU - Aleynikov, P.

AU - Alfier, A.

AU - Alkseev, A.

AU - Allinson, M.

AU - Alper, B.

AU - Alves, E.

AU - Ambrosino, G.

AU - Ambrosino, R.

AU - Amicucci, L.

AU - Amosov, V.

AU - Sundén, E. Andersson

AU - Angelone, M.

AU - Anghel, M.

AU - Angioni, C.

AU - Appel, L.

AU - Appelbee, C.

AU - Arena, P.

AU - Ariola, M.

AU - Arnichand, H.

AU - Arshad, S.

AU - Hakola, Antti

AU - Järvinen, Aaro

AU - Karhunen, Juuso

AU - Kim, H.T.

AU - Kim, H.S.

AU - Koivuranta, Seppo

AU - Lahtinen, Aki

AU - Likonen, Jari

AU - Liu, Y.

AU - Makkonen, T.

AU - Nordman, H.

AU - Salmi, Antti

AU - Santala, M.I.K.

AU - Sirén, Paula

AU - Tala, Tuomas

AU - JET Contributors

PY - 2018/6/13

Y1 - 2018/6/13

N2 - Recent studies (Maggi et al 2015 Nucl. Fusion 55 113031; Maggi et al 2017 Nucl. Fusion 57 116012) have shown that on JET with the Be/W ITER-like wall (JET-ILW) in high β discharges with high D2 gas rates, the inter-ELM temperature pedestal growth is saturated half way through the ELM cycle, leading to plasmas with reduced confinement, and that the linear MHD stability of these pedestals is inconsistent with the peeling-ballooning paradigm (Snyder et al 2002 Phys. Plasmas 9 2037-43; Wilson et al 2002 Phys. Plasmas 9 1277-86). In this paper, the inter-ELM evolution of the edge current density is investigated in a wide range of type I ELMy H-modes on JET-ILW. It is found that in discharges at a low gas rate, the peak edge bootstrap current continuously increases until the ELM crashes, while it saturates during the ELM cycle at high gas rates. The effect of current diffusion on the build-up of the edge current inter-ELM is assessed by simulating the Ohmic current contribution with the JETTO transport code. The simulations indicate that current diffusion contributes little to the time evolution of the total edge current in the second half of the ELM cycle and the total current is dominated by the bootstrap current. Therefore, current diffusion does not explain why JET-ILW type I ELMy pedestals at a high gas rate and high βN are found to be stable to peeling-ballooning modes.

AB - Recent studies (Maggi et al 2015 Nucl. Fusion 55 113031; Maggi et al 2017 Nucl. Fusion 57 116012) have shown that on JET with the Be/W ITER-like wall (JET-ILW) in high β discharges with high D2 gas rates, the inter-ELM temperature pedestal growth is saturated half way through the ELM cycle, leading to plasmas with reduced confinement, and that the linear MHD stability of these pedestals is inconsistent with the peeling-ballooning paradigm (Snyder et al 2002 Phys. Plasmas 9 2037-43; Wilson et al 2002 Phys. Plasmas 9 1277-86). In this paper, the inter-ELM evolution of the edge current density is investigated in a wide range of type I ELMy H-modes on JET-ILW. It is found that in discharges at a low gas rate, the peak edge bootstrap current continuously increases until the ELM crashes, while it saturates during the ELM cycle at high gas rates. The effect of current diffusion on the build-up of the edge current inter-ELM is assessed by simulating the Ohmic current contribution with the JETTO transport code. The simulations indicate that current diffusion contributes little to the time evolution of the total edge current in the second half of the ELM cycle and the total current is dominated by the bootstrap current. Therefore, current diffusion does not explain why JET-ILW type I ELMy pedestals at a high gas rate and high βN are found to be stable to peeling-ballooning modes.

KW - bootstrap current

KW - current diffusion

KW - edge current

KW - ELMs

KW - H-mode

KW - JET-ILW

KW - pedestal

UR - https://www.scopus.com/pages/publications/85050391677

U2 - 10.1088/1361-6587/aac7a9

DO - 10.1088/1361-6587/aac7a9

M3 - Article

AN - SCOPUS:85050391677

SN - 0741-3335

VL - 60

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

IS - 8

M1 - 085003

ER -

Inter-ELM evolution of the edge current density in JET-ILW type i ELMy H-mode plasmas

Abstract

Funding

UN SDGs

Keywords

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