MHD spectroscopy of JET plasmas with pellets via Alfvén eigenmodes

JET Contributors

doi:10.1088/1741-4326/aabb67

MHD spectroscopy of JET plasmas with pellets via Alfvén eigenmodes

JET Contributors

United Kingdom Atomic Energy Authority
University of Texas at Austin
Culham Science Centre
Jülich Research Centre
Institute for Plasma Research
University of Lisbon
Queen's University Belfast
University of Helsinki
Commissariat à l’énergie atomique et aux énergies alternatives
VTT Technical Research Centre of Finland Ltd.
National Institutes for Quantum Science and Technology
University of Naples Federico II
National Distance Education University
National Research Council of Italy
ITER
Russian Research Centre Kurchatov Institute
University of Naples Parthenope
Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile
Troitsk Institute for Innovation and Fusion Research
Uppsala University
The National Institute for Cryogenics and Isotopic Technology
Max Planck Institute for Plasma Physics
University of Catania
Fusion for Energy
National Institutes of Natural Sciences - National Institute for Fusion Science
Massachusetts Institute of Technology
Aalto University
University of Latvia
Imperial College London
CIEMAT
University of Oxford
EUROfusion Programme Management Unit
Oak Ridge National Laboratory
Karlsruhe Institute of Technology
University of York
KTH Royal Institute of Technology
Maritime University Of Szczecin
Institute of Nuclear Physics PAN
Czech Academy of Sciences
University of Trento
Swiss Federal Institute of Technology Lausanne
Wigner Research Centre for Physics
Comenius University
Lviv Polytechnic National University
University of Milan - Bicocca
The National Institute for Optoelectronics
Fourth State Research
Belgian Nuclear Research Center
National Centre for Nuclear Research
Princeton Plasma Physics Laboratory
Physique des Interactions Ioniques et Moléculaires
University of Cagliari
University of Warwick
Andrzej Soltan Institute for Nuclear Studies
Dutch Institute for Fundamental Energy Research
National Institute for Laser, Plasma and Radiation Physics
Ghent University
Jožef Stefan Institute
Université de Lorraine
CAS - Institute of Plasma Physics
University of California at San Diego
Royal Military Academy
Horia Hulubei National Institute of Physics and Nuclear Engineering
Chalmers University of Technology
European Commission
Technical University of Madrid
University of Campania Luigi Vanvitelli
Warsaw University of Technology
University of Basilicata
Barcelona Supercomputing Center (BSC)
Aix Marseille Université
University of Seville
Centro Brasileiro de Pesquisas Físicas
Aix-Marseille Université
University of Rome Tor Vergata
RAS - Ioffe Physico Technical Institute
General Atomics
University of Innsbruck
University of Toyama
University of Strathclyde
National Technical University of Athens
Tuscia University
Technical University of Denmark
Korea Advanced Institute of Science and Technology
Seoul National University
University College Cork
TU Wien
University of Opole
Daegu University
National Fusion Research Institute
Dublin City University
PELIN LLC
Arizona State University
Complutense University
University of Basel
Universidad Carlos III de Madrid
Consorzio CREATE
Demokritos National Centre for Scientific Research
Purdue University
Fluid and Plasma Dynamics
University of California
Universidade de São Paulo
Lithuanian Energy Institute
HRS Fusion
Polytechnic University of Turin
University of Cassino and Southern Lazio
University of Electronic Science and Technology of China

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

9 Scopus citations

Abstract

Alfvén eigenmodes (AEs) are routinely seen in present-day tokamaks and stellarators with energetic particles and they represent an attractive form of MHD spectroscopy that provides valuable information on background plasma and on the energetic particles. Possible use of AEs is assessed for MHD spectroscopy of plasma with high-velocity pellet injection employed for fuelling the plasma core. Diagnostics of temporal evolution of the ablated pellets, as well as physics effects determining the diffusion/relaxation of the post pellet profile are of high importance for validating the pellet models and extrapolating them towards ITER. In this paper, JET discharges with ICRH-driven AEs and pellets launched from outboard and inboard tracks are considered. During the pellet injection, an increase in plasma density on a time scale ≪ 50 ms occurs, and several effects on AEs are observed: (1) frequency of the AEs throughout the pellet injection sweeps down by as much as ∼30%, (2) the AE amplitudes increase during the AE frequency sweeping, and (3) spectrum of toroidal mode numbers of the AEs broadens significantly after the pellet injection. The effects observed are interpreted in terms of a rise in plasma density and an enhancement of the mode amplitude resulting from the resonance sweeping during the pellet injection.

Original language	English
Article number	082008
Journal	Nuclear Fusion
Volume	58
Issue number	8
DOIs	https://doi.org/10.1088/1741-4326/aabb67
State	Published - 29 Jun 2018
Externally published	Yes

Bibliographical note

Publisher Copyright:
© EURATOM 2018.

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 and from the RCUK Energy Programme (grant number EP/P012450/1). To obtain further information on the data and models underlying this paper please contact [email protected]. The views and opinions expressed herein do not necessarily reflect those of the European Commission.

Funders	Funder number
Horizon 2020 Framework Programme	633053
H2020 Euratom
Research Councils UK	EP/P012450/1

Keywords

Alfven
MHD
frequency sweeping
fusion
subcritical
tokamak

Access to Document

10.1088/1741-4326/aabb67

Cite this

@article{33146a40ff2f49769a62b0241f7e7fd7,

title = "MHD spectroscopy of JET plasmas with pellets via Alfv{\'e}n eigenmodes",

abstract = "Alfv{\'e}n eigenmodes (AEs) are routinely seen in present-day tokamaks and stellarators with energetic particles and they represent an attractive form of MHD spectroscopy that provides valuable information on background plasma and on the energetic particles. Possible use of AEs is assessed for MHD spectroscopy of plasma with high-velocity pellet injection employed for fuelling the plasma core. Diagnostics of temporal evolution of the ablated pellets, as well as physics effects determining the diffusion/relaxation of the post pellet profile are of high importance for validating the pellet models and extrapolating them towards ITER. In this paper, JET discharges with ICRH-driven AEs and pellets launched from outboard and inboard tracks are considered. During the pellet injection, an increase in plasma density on a time scale ≪ 50 ms occurs, and several effects on AEs are observed: (1) frequency of the AEs throughout the pellet injection sweeps down by as much as ∼30\%, (2) the AE amplitudes increase during the AE frequency sweeping, and (3) spectrum of toroidal mode numbers of the AEs broadens significantly after the pellet injection. The effects observed are interpreted in terms of a rise in plasma density and an enhancement of the mode amplitude resulting from the resonance sweeping during the pellet injection.",

keywords = "Alfven, MHD, frequency sweeping, fusion, subcritical, tokamak",

author = "\{JET Contributors\} and Sharapov, \{S. E.\} and Oliver, \{H. J.C.\} and Breizman, \{B. N.\} and M. Fitzgerald and L. Garzotti 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 L. Aho-Mantila and N. Aiba and M. 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 A. Ash and N. Ashikawa and V. Aslanyan and O. Asunta and F. Auriemma and Y. Austin and L. Avotina and Axton, \{M. D.\} and C. Ayres and D. Borodin",

note = "Publisher Copyright: {\textcopyright} EURATOM 2018.",

year = "2018",

month = jun,

day = "29",

doi = "10.1088/1741-4326/aabb67",

language = "אנגלית",

volume = "58",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "IOP Publishing Ltd.",

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TY - JOUR

T1 - MHD spectroscopy of JET plasmas with pellets via Alfvén eigenmodes

AU - JET Contributors

AU - Sharapov, S. E.

AU - Oliver, H. J.C.

AU - Breizman, B. N.

AU - Fitzgerald, M.

AU - Garzotti, L.

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, L.

AU - Aiba, N.

AU - Airila, M.

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 - Ash, A.

AU - Ashikawa, N.

AU - Aslanyan, V.

AU - Asunta, O.

AU - Auriemma, F.

AU - Austin, Y.

AU - Avotina, L.

AU - Axton, M. D.

AU - Ayres, C.

AU - Borodin, D.

PY - 2018/6/29

Y1 - 2018/6/29

N2 - Alfvén eigenmodes (AEs) are routinely seen in present-day tokamaks and stellarators with energetic particles and they represent an attractive form of MHD spectroscopy that provides valuable information on background plasma and on the energetic particles. Possible use of AEs is assessed for MHD spectroscopy of plasma with high-velocity pellet injection employed for fuelling the plasma core. Diagnostics of temporal evolution of the ablated pellets, as well as physics effects determining the diffusion/relaxation of the post pellet profile are of high importance for validating the pellet models and extrapolating them towards ITER. In this paper, JET discharges with ICRH-driven AEs and pellets launched from outboard and inboard tracks are considered. During the pellet injection, an increase in plasma density on a time scale ≪ 50 ms occurs, and several effects on AEs are observed: (1) frequency of the AEs throughout the pellet injection sweeps down by as much as ∼30%, (2) the AE amplitudes increase during the AE frequency sweeping, and (3) spectrum of toroidal mode numbers of the AEs broadens significantly after the pellet injection. The effects observed are interpreted in terms of a rise in plasma density and an enhancement of the mode amplitude resulting from the resonance sweeping during the pellet injection.

AB - Alfvén eigenmodes (AEs) are routinely seen in present-day tokamaks and stellarators with energetic particles and they represent an attractive form of MHD spectroscopy that provides valuable information on background plasma and on the energetic particles. Possible use of AEs is assessed for MHD spectroscopy of plasma with high-velocity pellet injection employed for fuelling the plasma core. Diagnostics of temporal evolution of the ablated pellets, as well as physics effects determining the diffusion/relaxation of the post pellet profile are of high importance for validating the pellet models and extrapolating them towards ITER. In this paper, JET discharges with ICRH-driven AEs and pellets launched from outboard and inboard tracks are considered. During the pellet injection, an increase in plasma density on a time scale ≪ 50 ms occurs, and several effects on AEs are observed: (1) frequency of the AEs throughout the pellet injection sweeps down by as much as ∼30%, (2) the AE amplitudes increase during the AE frequency sweeping, and (3) spectrum of toroidal mode numbers of the AEs broadens significantly after the pellet injection. The effects observed are interpreted in terms of a rise in plasma density and an enhancement of the mode amplitude resulting from the resonance sweeping during the pellet injection.

KW - Alfven

KW - MHD

KW - frequency sweeping

KW - fusion

KW - subcritical

KW - tokamak

UR - https://www.scopus.com/pages/publications/85050356733

U2 - 10.1088/1741-4326/aabb67

DO - 10.1088/1741-4326/aabb67

M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???

AN - SCOPUS:85050356733

SN - 0029-5515

VL - 58

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 8

M1 - 082008

ER -

MHD spectroscopy of JET plasmas with pellets via Alfvén eigenmodes

Abstract

Bibliographical note

Funding

Keywords

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