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Results from the Alfvén Eigenmode Active Diagnostic during the 2019-2020 JET deuterium campaign

Journal Article · · Plasma Physics and Controlled Fusion
 [1];  [2];  [3];  [3];  [4];  [2];  [2]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); OSTI
  2. Ecole Polytechnique Federale Lausanne (EPFL) (Switzerland)
  3. Culham Science Centre, Abingdon (United Kingdom). Culham Centre for Fusion Energy (CCFE)
  4. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

This paper presents results of extensive analysis of mode excitation observed during the operation of the Alfvén Eigenmode Active Diagnostic (AEAD) in the JET tokamak during the 2019-2020 deuterium campaign. Here, six of eight toroidally spaced antennas, each with independent power and phasing, were successful in actively exciting stable MHD modes in 479 plasmas. In total, magnetic resonances were detected with up to fourteen fast magnetic probes. In this work, we present the calculations of resonant frequencies $$f_0$$, damping rates γ < 0, and toroidal mode numbers $$\textit{n}$$, spanning the parameter ranges $$f_0$$ ≈ 30–250 kHz, –γ ≈ 0–13 kHz, and $$\vert n \vert \leq {30}$$. In general, good agreement is seen between the resonant and the calculated toroidal Alfvén Eigenmode frequencies, and between the toroidal mode numbers applied by the AEAD and estimated of the excited resonances. We note several trends in the database: the probability of resonance detection decreases with plasma current and external heating power; the normalized damping rate increases with edge safety factor but decreases with external heating. These results provide key information to prepare future experimental campaigns and to better understand the physics of excitation and damping of Alfvén Eigenmodes in the presence of alpha particles during the upcoming DT campaign, thereby extrapolating with confidence to future tokamaks.

Research Organization:
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES); Euratom
Contributing Organization:
JET Contributors
Grant/Contract Number:
FG02-99ER54563; AC02-05CH11231; AC05-00OR22725
OSTI ID:
1897186
Alternate ID(s):
OSTI ID: 1660783
OSTI ID: 23028636
Journal Information:
Plasma Physics and Controlled Fusion, Journal Name: Plasma Physics and Controlled Fusion Journal Issue: 11 Vol. 62; ISSN 0741-3335
Publisher:
IOP ScienceCopyright Statement
Country of Publication:
United States
Language:
English

References (44)

Introduction to the interaction between energetic particles and Alfven eigenmodes in toroidal plasmas journal December 2018
The standard error of a weighted mean concentration—I. Bootstrapping vs other methods journal June 1995
Isotope mass scaling of AE damping rates in the JET tokamak plasmas journal January 2000
The JET Alfvén Eigenmode Local Manager for the real-time detection and tracking of a frequency-degenerate spectrum of MHD instabilities journal June 2011
SparSpec : a new method for fitting multiple sinusoids with irregularly sampled data journal October 2006
Modeling of diamagnetic stabilization of ideal magnetohydrodynamic instabilities associated with the transport barrier journal October 2001
Diagnosis and study of Alfvén eigenmodes stability in JET (invited) journal March 2003
Axisymmetric global Alfvén eigenmodes within the ellipticity-induced frequency gap in the Joint European Torus journal December 2017
Kinetic description of Alfvén wave heating journal January 1982
Stable ellipticity-induced Alfvén eigenmodes in the Joint European Torus journal October 1997
Prediction of Alfvén eigenmode dampings in the Joint European Torus journal August 1998
Fast particles-wave interaction in the Alfvén frequency range on the Joint European Torus tokamak journal May 2000
Reconstruction of current profile parameters and plasma shapes in tokamaks journal November 1985
Overview of Alfven eigenmode experiments in JET journal December 1995
Chapter 5: Physics of energetic ions journal December 1999
The effect of plasma shaping on the damping of low n Alfvén eigenmodes in JET tokamak plasmas journal July 2001
Experimental test of damping models for n  1 toroidal Alfv n eigenmodes in JET journal June 2003
Measurement of the damping rate of n 1 toroidal Alfv n eigenmodes as a function of the neutral beam heating power and plasma   on JET journal August 2003
Experimental study of the dependence of the damping rate of n = 1 TAEs on the on-axis safety factor and toroidal rotation shear journal August 2005
Measurement of the instability threshold for toroidal Alfvén eigenmodes in JET plasmas with forward and reversed magnetic field journal July 2006
The dependence of the damping rate of medium- n toroidal Alfvén eigenmodes on the edge plasma elongation in JET journal July 2010
Optimization of the active MHD spectroscopy system on JET for the excitation of individual intermediate and high- n Alfvén eigenmodes journal July 2010
Recent JET experiments on Alfvén eigenmodes with intermediate toroidal mode numbers: measurements and modelling of n = 3 toroidal Alfvén eigenmodes with the TAEFL code journal April 2011
Analysis of damping rate measurements of toroidal Alfvén eigenmodes as a function of n : part II journal January 2012
Plasma isotopic effect on the damping rate of toroidal Alfvén eigenmodes with intermediate toroidal mode numbers journal September 2012
The upgraded JET toroidal Alfvén eigenmode diagnostic system journal August 2016
Excitation of global eigenmodes of the Alfven wave in Tokamaks journal September 1982
Alfvén eigenmode experiments in tokamaks and stellarators journal December 1997
A review of Alfvén eigenmode observations in toroidal plasmas journal January 1999
Gyrokinetic modelling of macro-instabilities in high performance tokamak plasmas journal November 2001
MHD spectroscopy journal November 2002
Alfvén mode stability and wave–particle interaction in the JET tokamak: prospects for scenario development and control schemes in burning plasma experiments journal May 2004
A sparsity-based method for the analysis of magnetic fluctuations in unevenly-spaced Mirnov coils journal October 2008
Active excitation and damping rate measurement of intermediate- n toroidal Alfvén eigenmodes in JET, C-Mod and MAST plasmas journal June 2010
Scenario development for the observation of alpha-driven instabilities in JET DT plasmas journal June 2018
TAE stability calculations compared to TAE antenna results in JET journal June 2018
Gyrokinetic simulations of toroidal Alfvén eigenmodes excited by energetic ions and external antennas on the Joint European Torus journal December 2018
Direct Measurement of the Damping of Toroidicity-Induced Alfvén Eigenmodes journal July 1995
Observation of Multiple Kinetic Alfvén Eigenmodes journal February 1996
Isoparametric Bicubic Hermite Elements for Solution of the Grad-Shafranov Equation journal March 1991
The JET Alfvén Eigenmode Local Manager for the real-time detection and tracking of MHD instabilities journal December 2010
Implementation of a Novel Real-Time Controller for the Detection and Tracking of Magneto-Hydrodynamic Instabilities on the JET Tokamak journal January 2014
Results from the Alfven Eigenmode Active Diagnostic during the 2019-2020 JET deuterium campaign dataset January 2021
Experimental studies of plasma-antenna coupling with the JET Alfven Eigenmode Active Diagnostic dataset January 2021

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