Nonlinear interaction of Alfvénic instabilities and turbulence via the modification of the equilibrium profiles

Biancalani, A.; Bottino, A.; Del Sarto, D.; Falessi, M.V.; Hayward-Schneider, T.; Lauber, P.; Mishchenko, A.; Rettino, B.; Sama, J.N.; Vannini, F.; Villard, L.; Wang, X.; Zonca, F.; ,

doi:10.1017/s0022377823001137

Cited by 3 publications

(1 citation statement)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to increasingly realistic non-linear global gyrokinetic simulations [1][2][3][4][5][6], a hierarchy of theory-based reduced models is highly desirable to complement the predictions concerning the performance of future burning plasmas. Large parameter scans, sensitivity studies, and multi-scale physics describing energetic particle (EP) transport on neoclassical transport time scales require tools that go beyond what is presently feasible with first-principles numerical codes.…”

Section: Introductionmentioning

confidence: 99%

ATEP: an advanced transport model for energetic particles

Lauber,

Falessi,

Meng

et al. 2024

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

In this paper we report on the implementation and verification of a phase- space resolved energetic particle (EP) transport model. It is based on a first-principle theoretical framework, i.e. the system of non-linear gyrokinetic equations and the related transport equations. Its focus is primarily directed toward understanding the meso-scale character of EPs and its consequences. Compared to the conventional description of thermal radial transport via a one-dimensional radial diffusion equation, the newly developed model is three-dimensional using canonical constants-of-motion (CoM) variables. The model does not assume diffusive processes to be dominant a priori, instead the EP fluxes are self-consistently calculated and directly evolved in CoM space. We use the EP-Stability workflow and the HAGIS code to determine the phase space fluxes explicitly either in the limit of constant mode amplitudes or an energy-conserving quasi-linear model. As an application of the model the transport of neutral-beam-generated EPs due to a toroidal Alfv ́en eigenmode in an ITER plasma is investigated. As there are no sources and collisions taken into account so far (for an extension of the model see the companion paper ref. [1]), the results cannot be considered as an exhaustive study, but rather as a practical demonstration of the conceptual framework on the way to a comprehensive reduced description of burning plasmas.

show abstract

Section: Introductionmentioning

confidence: 99%

ATEP: an advanced transport model for energetic particles

Lauber,

Falessi,

Meng

et al. 2024

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

show abstract

Ion temperature gradient mode mitigation by energetic particles, mediated by forced-driven zonal flows

Sama,

Biancalani,

Bottino

et al. 2024

Physics of Plasmas

View full text Add to dashboard Cite

In this work, we use the global electromagnetic and electrostatic gyro kinetic approaches to investigate the effects of zonal flows forced-driven by Alfvén modes due to their excitation by energetic particles on the dynamics of ITG (ion temperature gradient) instabilities. The equilibrium of the 92416 JET tokamak shot is considered. The linear, nonlinear Alfvén modes, and the zonal flow dynamics are investigated, and their respective radial structures and saturation levels are reported. ITG dynamics in the presence of the zonal flows excited by these Alfvén modes are also investigated. The zonal flows forced-driven by Alfvén modes can significantly impact the ITG dynamics. A zonal flow amplitude scan reveals the existence of an inverse relation between the zonal flow amplitude and the ITG growth rate. These results indicate that forced-driven zonal flows can be an important indirect part of turbulence mitigation due to the injection of energetic particles.

show abstract

Internal transport barrier triggered by phase synchronization of zonal flow with energetic particle modes

Ghizzo,

Del Sarto,

Sama

et al. 2024

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

The suppression of the microturbulence associatedto the emergence of a spontaneous internal transport barrier has beenrecently demonstrated in a system showing a possible amplificationof the zonal flow component in the low-frequency regime $\left[\right.$A.Ghizzo and D. Del Sarto D 2023 \textit{Nucl. Fusion}\textbf{63} 104002$\left.\right]$.We use here numerical experiments performed with a ``particle mode''model based on a double average over the fast cyclotron phaseand over the bounce (or transit) phase to show the major role playedby energetic particles and shear flows in this scenario. \textquotedbl Particlemodes\textquotedbl{} are meant here as classes of particles, identifiedby some adiabatic invariant after a gyro-average procedure, whichare associated to the description of some specific linear modes ofthe plasma. The introduction of energetic circulating ions or shearflows into the system makes a larger number of particle modes beinginvolved in the synchronization process. A global synchronizationof the Fourier modes of the turbulent spectrum can be this way achieved.This process allows for a bifurcation towards self-organization, whichis associated to the emergence of a staircase-like structure. Thisis known to be an essential element in the modification of the zonalflow pattern in phase space during the suppression of microturbulencein tokamaks.

show abstract

Nonlinear interaction of Alfvénic instabilities and turbulence via the modification of the equilibrium profiles

Cited by 3 publications

References 43 publications

ATEP: an advanced transport model for energetic particles

ATEP: an advanced transport model for energetic particles

Ion temperature gradient mode mitigation by energetic particles, mediated by forced-driven zonal flows

Internal transport barrier triggered by phase synchronization of zonal flow with energetic particle modes

Contact Info

Product

Resources

About