TAE stability calculations compared to TAE antenna results in JET

F. Nabais; V. Aslanyan; D. Borba; R. Coelho; R. Dumont; J. Ferreira; A. Figueiredo; M. Fitzgerald; E. Lerche; J. Mailloux; M. Mantsinen; P. Rodrigues; M. Porkolab; P. Puglia; S.E. Sharapov; 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:10.1088/1741-4326/aabdbd

TAE stability calculations compared to TAE antenna results in JET

F. Nabais^*, V. Aslanyan, D. Borba, R. Coelho, R. Dumont, J. Ferreira, A. Figueiredo, M. Fitzgerald, E. Lerche, J. Mailloux, M. Mantsinen, P. Rodrigues, M. Porkolab, P. Puglia, S.E. Sharapov, Leena Aho-Mantila, Markus Airila, Antti Hakola, Aaro Järvinen, Juuso KarhunenSeppo Koivuranta, Aki Lahtinen, Jari Likonen, Antti Salmi, Paula Sirén, Tuomas Tala, JET Contributors

^*Corresponding author for this work

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

12 Citations (Scopus)

Abstract

The excitation of modes in the toroidal Alfvén eigenmodes (TAE) gap by an external antenna can be modelled by a driven damped harmonic oscillator. By performing a frequency scan it is possible to determine the damping rate of the mode through the quality factor. This method has been employed in recent Joint European Torus (JET) experiments dedicated to scenario development for the observation of alpha-driven instabilities in JET DT plasmas (i.e. plasmas composed by Deuterium and Tritium). However, the toroidal mode number n of the mode for which the measurements were performed could not be determined experimentally. The value of the damping obtained through experimental measurements for a selected time slice is then compared with those obtained from calculations performed by numerical codes for different modes with frequencies close to the experimental frequency of the antenna. This paper describes the modelling method and presents the numerical simulations carried out using a suite of codes to calculate the damping of TAE, which are compared with the value measured experimentally. The radial structures of these modes are first calculated with the ideal magnetohydrodynamic (MHD) code MISHKA. For each of these modes, the damping on thermal ions and thermal electrons and the contribution to the mode growth rate resulting from the resonant interaction with the ion cyclotron resonance heating (ICRH) accelerated ion population are calculated using the drift-kinetic code CASTOR-K. The radiative damping is calculated by using a complex resistivity in the resistive MHD code CASTOR code and the continuum damping is estimated using also the CASTOR code through the standard method of making the real part of the resistivity tend to zero. It was found the radiative damping is largely dominant over all other effects, except for the n = 3 TAE. The overall damping calculated numerically is consistent with the damping measured experimentally.

Original language	English
Article number	082007
Journal	Nuclear Fusion
Volume	58
Issue number	8
DOIs	https://doi.org/10.1088/1741-4326/aabdbd
Publication status	Published - 29 Jun 2018
MoE publication type	A1 Journal article-refereed

Funding

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. IST activities also received financial support from ‘Fundação para a Ciência e Tecnologia’ through project UID/FIS/50010/2013. Support for the US group was provided by the US DOE under Grant Number DE-FG02-99ER54563.

Keywords

Alfvén eigemodes
energetic particles
TAE antenna
tokamaks

UN SDGs

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

Access to Document

10.1088/1741-4326/aabdbd

Cite this

Nabais, F., Aslanyan, V., Borba, D., Coelho, R., Dumont, R., Ferreira, J., Figueiredo, A., Fitzgerald, M., Lerche, E., Mailloux, J., Mantsinen, M., Rodrigues, P., Porkolab, M., Puglia, P., Sharapov, S. E., Aho-Mantila, L., Airila, M., Hakola, A., Järvinen, A., ... JET Contributors (2018). TAE stability calculations compared to TAE antenna results in JET. Nuclear Fusion, 58(8), Article 082007. https://doi.org/10.1088/1741-4326/aabdbd

@article{e3de9bfb422b406f9bb5143adaaae1af,

title = "TAE stability calculations compared to TAE antenna results in JET",

abstract = "The excitation of modes in the toroidal Alfv{\'e}n eigenmodes (TAE) gap by an external antenna can be modelled by a driven damped harmonic oscillator. By performing a frequency scan it is possible to determine the damping rate of the mode through the quality factor. This method has been employed in recent Joint European Torus (JET) experiments dedicated to scenario development for the observation of alpha-driven instabilities in JET DT plasmas (i.e. plasmas composed by Deuterium and Tritium). However, the toroidal mode number n of the mode for which the measurements were performed could not be determined experimentally. The value of the damping obtained through experimental measurements for a selected time slice is then compared with those obtained from calculations performed by numerical codes for different modes with frequencies close to the experimental frequency of the antenna. This paper describes the modelling method and presents the numerical simulations carried out using a suite of codes to calculate the damping of TAE, which are compared with the value measured experimentally. The radial structures of these modes are first calculated with the ideal magnetohydrodynamic (MHD) code MISHKA. For each of these modes, the damping on thermal ions and thermal electrons and the contribution to the mode growth rate resulting from the resonant interaction with the ion cyclotron resonance heating (ICRH) accelerated ion population are calculated using the drift-kinetic code CASTOR-K. The radiative damping is calculated by using a complex resistivity in the resistive MHD code CASTOR code and the continuum damping is estimated using also the CASTOR code through the standard method of making the real part of the resistivity tend to zero. It was found the radiative damping is largely dominant over all other effects, except for the n = 3 TAE. The overall damping calculated numerically is consistent with the damping measured experimentally.",

keywords = "Alfv{\'e}n eigemodes, energetic particles, TAE antenna, tokamaks",

author = "F. Nabais and V. Aslanyan and D. Borba and R. Coelho and R. Dumont and J. Ferreira and A. Figueiredo and M. Fitzgerald and E. Lerche and J. Mailloux and M. Mantsinen and P. Rodrigues and M. Porkolab and P. Puglia and S.E. Sharapov 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 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 = "Funding Information: The views and opinions expressed herein do not necessarily reflect those of the European Commission. Support for the US group was provided by the US DOE under Grant Number DE-FG02-99ER54563. Publisher Copyright: {\textcopyright} EURATOM 2018.",

year = "2018",

month = jun,

day = "29",

doi = "10.1088/1741-4326/aabdbd",

language = "English",

volume = "58",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "Institute of Physics IOP",

number = "8",

}

Nabais, F, Aslanyan, V, Borba, D, Coelho, R, Dumont, R, Ferreira, J, Figueiredo, A, Fitzgerald, M, Lerche, E, Mailloux, J, Mantsinen, M, Rodrigues, P, Porkolab, M, Puglia, P, Sharapov, SE, 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, 'TAE stability calculations compared to TAE antenna results in JET', Nuclear Fusion, vol. 58, no. 8, 082007. https://doi.org/10.1088/1741-4326/aabdbd

TY - JOUR

T1 - TAE stability calculations compared to TAE antenna results in JET

AU - Nabais, F.

AU - Aslanyan, V.

AU - Borba, D.

AU - Coelho, R.

AU - Dumont, R.

AU - Ferreira, J.

AU - Figueiredo, A.

AU - Fitzgerald, M.

AU - Lerche, E.

AU - Mailloux, J.

AU - Mantsinen, M.

AU - Rodrigues, P.

AU - Porkolab, M.

AU - Puglia, P.

AU - Sharapov, S.E.

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 - 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

N1 - Funding Information: The views and opinions expressed herein do not necessarily reflect those of the European Commission. Support for the US group was provided by the US DOE under Grant Number DE-FG02-99ER54563. Publisher Copyright: © EURATOM 2018.

PY - 2018/6/29

Y1 - 2018/6/29

N2 - The excitation of modes in the toroidal Alfvén eigenmodes (TAE) gap by an external antenna can be modelled by a driven damped harmonic oscillator. By performing a frequency scan it is possible to determine the damping rate of the mode through the quality factor. This method has been employed in recent Joint European Torus (JET) experiments dedicated to scenario development for the observation of alpha-driven instabilities in JET DT plasmas (i.e. plasmas composed by Deuterium and Tritium). However, the toroidal mode number n of the mode for which the measurements were performed could not be determined experimentally. The value of the damping obtained through experimental measurements for a selected time slice is then compared with those obtained from calculations performed by numerical codes for different modes with frequencies close to the experimental frequency of the antenna. This paper describes the modelling method and presents the numerical simulations carried out using a suite of codes to calculate the damping of TAE, which are compared with the value measured experimentally. The radial structures of these modes are first calculated with the ideal magnetohydrodynamic (MHD) code MISHKA. For each of these modes, the damping on thermal ions and thermal electrons and the contribution to the mode growth rate resulting from the resonant interaction with the ion cyclotron resonance heating (ICRH) accelerated ion population are calculated using the drift-kinetic code CASTOR-K. The radiative damping is calculated by using a complex resistivity in the resistive MHD code CASTOR code and the continuum damping is estimated using also the CASTOR code through the standard method of making the real part of the resistivity tend to zero. It was found the radiative damping is largely dominant over all other effects, except for the n = 3 TAE. The overall damping calculated numerically is consistent with the damping measured experimentally.

AB - The excitation of modes in the toroidal Alfvén eigenmodes (TAE) gap by an external antenna can be modelled by a driven damped harmonic oscillator. By performing a frequency scan it is possible to determine the damping rate of the mode through the quality factor. This method has been employed in recent Joint European Torus (JET) experiments dedicated to scenario development for the observation of alpha-driven instabilities in JET DT plasmas (i.e. plasmas composed by Deuterium and Tritium). However, the toroidal mode number n of the mode for which the measurements were performed could not be determined experimentally. The value of the damping obtained through experimental measurements for a selected time slice is then compared with those obtained from calculations performed by numerical codes for different modes with frequencies close to the experimental frequency of the antenna. This paper describes the modelling method and presents the numerical simulations carried out using a suite of codes to calculate the damping of TAE, which are compared with the value measured experimentally. The radial structures of these modes are first calculated with the ideal magnetohydrodynamic (MHD) code MISHKA. For each of these modes, the damping on thermal ions and thermal electrons and the contribution to the mode growth rate resulting from the resonant interaction with the ion cyclotron resonance heating (ICRH) accelerated ion population are calculated using the drift-kinetic code CASTOR-K. The radiative damping is calculated by using a complex resistivity in the resistive MHD code CASTOR code and the continuum damping is estimated using also the CASTOR code through the standard method of making the real part of the resistivity tend to zero. It was found the radiative damping is largely dominant over all other effects, except for the n = 3 TAE. The overall damping calculated numerically is consistent with the damping measured experimentally.

KW - Alfvén eigemodes

KW - energetic particles

KW - TAE antenna

KW - tokamaks

UR - http://www.scopus.com/inward/record.url?scp=85050380018&partnerID=8YFLogxK

U2 - 10.1088/1741-4326/aabdbd

DO - 10.1088/1741-4326/aabdbd

M3 - Article

AN - SCOPUS:85050380018

SN - 0029-5515

VL - 58

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 8

M1 - 082007

ER -

TAE stability calculations compared to TAE antenna results in JET

Abstract

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Keywords

UN SDGs

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