7 papers
On the effect of beating during nonlinear frequency chirping
Andreas Bierwage, Roscoe B. White, Vinícius N. Duarte
Spectral analyses of energetic particle (EP) driven bursts of MHD fluctuations in magnetically confined plasmas often exhibit multiple simultaneous chirps. While the superposition…
A class of solutions of the two-dimensional Toda lattice equation
Vinicius Duarte
A method is proposed to systematically generate solutions of the two-dimensional Toda lattice equation in terms of previously known solutions of the two-dimensi…
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…
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…
Analytical nonlinear collisional dynamics of near-threshold eigenmodes
Vinicius Duarte, Nikolai Gorelenkov
A closed-form analytical solution is found for the nonlinear dynamics of isolated, near-threshold waves in the presence of strong scattering. The proposed solution can be useful in…
Resonance line broadened quasilinear (RBQ) model for fast ion distribution relaxation due to Alfvénic eigenmodes
Nikolai Gorelenkov, Vinicius Duarte, Mario Podesta +1
The burning plasma performance is limited by the confinement of the superalfvenic fusion products such as alpha particles and the auxiliary heating ions capable of exciting the Alf…