53 citations · 190 across the 14 of their papers we have counts for
15 papers
Perturbative model for the saturation of energetic-particle-driven modes limited by self-generated zonal modes
Tommaso Barberis, Vinícius N. Duarte, Eamon J. Hartigan-O'Connor +1
We present a simplified approach enforcing energy conservation to incorporate the effects of zonal modes alongside wave-particle nonlinearities in the determination of the saturati…
Saturation of fishbone instability through zonal flows driven by energetic particle transport in tokamak plasmas
G. Brochard, C. Liu, X. Wei +17
Gyrokinetic and kinetic-MHD simulations are performed for the fishbone instability in the DIII-D discharge #178631, chosen for validation of first-principles simulations to predict…
Thermal ion kinetic effects and Landau damping in fishbone modes
Chang Liu, Stephen C. Jardin, Jian Bao +4
The kinetic-MHD hybrid simulation approach for macroscopic instabilities in plasmas can be extended to include the kinetic effects of both thermal ions and energetic ions. The new…
Hybrid simulations of sub-cyclotron compressional and global Alfvén Eigenmode stability in spherical tokamaks
J. B. Lestz, E. V. Belova, N. N. Gorelenkov
A comprehensive numerical study has been conducted in order to investigate the stability of beam-driven, sub-cyclotron frequency compressional (CAE) and global (GAE) Alfvén Eigenmo…
Shifting and splitting of resonance lines due to dynamical friction in plasmas
V. N. Duarte, J. B. Lestz, N. N. Gorelenkov +1
A quasilinear plasma transport theory that incorporates Fokker-Planck dynamical friction (drag) and pitch angle scattering is self-consistently derived from first principles for an…
Microturbulence-mediated route for energetic ion transport and Alfvénic mode intermittency in tokamaks
Nikolai Gorelenkov, Vinicius Duarte
We report on a theoretical discovery of new regimes of Alfvén eigenmode (AE) induced fast ion transport in tokamak plasmas, where microturbulence plays the role of a mediator of fa…
Theory and Simulations of Compressional and Global Alfven Eigenmode Stability in Spherical Tokamaks
J. B. Lestz
Neutral-beam-driven, sub-cyclotron compressional (CAE) and global (GAE) \Alfven eigenmodes are routinely excited in spherical tokamaks such as NSTX(-U) and MAST, have been observed…
Analytic stability boundaries for compressional and global Alfvén eigenmodes driven by fast ions. II. Interaction via Landau resonance
J. B. Lestz, N. N. Gorelenkov, E. V. Belova +2
Conditions for net fast ion drive are derived for beam-driven, co-propagating, sub-cyclotron compressional (CAE) and global (GAE) Alfvén eigenmodes driven by the Landau resonance w…
Analytic stability boundaries for compressional and global Alfvén eigenmodes driven by fast ions. I. Interaction via ordinary and anomalous cyclotron resonances
J. B. Lestz, N. N. Gorelenkov, E. V. Belova +2
Conditions for net fast ion drive are derived for beam-driven, sub-cyclotron compressional (CAE) and global (GAE) Alfvén eigenmodes, such as those routinely observed in spherical t…
Machine learning characterisation of Alfvénic and sub-Alfvénic chirping and correlation with fast ion loss at NSTX
Benjamin J. Q. Woods, Vinícius N. Duarte, Eric D. Fredrickson +3
Abrupt large events in the Alfvénic and sub-Alfvénic frequency bands in tokamaks are typically correlated with increased fast ion loss. Here, machine learning is used to speed up t…
Study of the likelihood of Alfvénic mode bifurcation in NSTX and predictions for ITER baseline scenarios
Vinicius Duarte, Nikolai Gorelenkov, Mirjam Schneller +3
Rare Alfvénic wave transitions between fixed-frequency and chirping phases are identified in NSTX, where Alfvénic waves are normally observed to exhibit either chirping or avalanch…
Energetic-particle-modified global Alfvén eigenmodes
J. B. Lestz, E. V. Belova, N. N. Gorelenkov
Fully self-consistent hybrid MHD/particle simulations reveal strong energetic particle modifications to sub-cyclotron global Alfvén eigenmodes (GAE) in low-aspect ratio, NSTX-like…
Onset of nonlinear structures due to eigenmode destabilization in tokamak plasmas
Vinicius Duarte, Herbert Berk, Nikolai Gorelenkov +5
A general methodology is proposed to differentiate the likelihood of energetic-particle-driven instabilities to produce frequency chirping or fixed-frequency oscillations. The meth…
Prediction of Nonlinear Evolution Character of Energetic-Particle-Driven Instabilities
Vinicius Duarte, Herbert Berk, Nikolai Gorelenkov +7
A general criterion is proposed and found to successfully predict the emergence of chirping oscillations of unstable Alfvénic eigenmodes in tokamak plasma experiments. The model in…
Comparison of methods for numerical calculation of continuum damping
George Bowden, Axel Könies, Matthew Hole +2
Continuum resonance damping is an important factor in determining the stability of certain global modes in fusion plasmas. A number of analytic and numerical approaches have been d…