Non-Maxwellian fast particle effects in gyrokinetic GENE simulations

@article{Siena2018NonMaxwellianFP,
  title={Non-Maxwellian fast particle effects in gyrokinetic GENE simulations},
  author={Alessandro Di Siena and T. Gorler and H. Doerk and Roberto Bilato and J. Citrin and Thomas Johnson and M. Schneider and Emanuele Poli and J. E. T. Contributors},
  journal={arXiv: Plasma Physics},
  year={2018}
}
Fast ions have recently been found to significantly impact and partially suppress plasma turbulence both in experimental and numerical studies in a number of scenarios. Understanding the underlying physics and identifying the range of their beneficial effect is an essential task for future fusion reactors, where highly energetic ions are generated through fusion reactions and external heating schemes. However, in many of the gyrokinetic codes fast ions are, for simplicity, treated as equivalent… 

Figures and Tables from this paper

Fast ions and turbulent particle transport in tokamaks

The presence of highly energetic (fast) ions, be it fusion born alpha particles or ions accelerated by auxiliary heating schemes, can affect the heating and transport of all particles in the plasma

Gyrokinetic study of transport suppression in JET plasmas with MeV-ions and toroidal Alfvén eigenmodes

The impact of fast ions, generated in the MeV-range through the efficient application of the three-ion scheme in JET plasmas, on the turbulence properties is presented through complex numerical

Nonlinear electromagnetic interplay between fast ions and ion-temperature-gradient plasma turbulence

In strong electromagnetic regimes, gyrokinetic simulations have linked a substantial ion-scale turbulence stabilization to the presence of supra-thermal particles, capturing qualitatively well the

Impact of fast ions on density peaking in JET: fluid and gyrokinetic modeling

The effect of fast ions on turbulent particle transport, driven by ion temperature gradient (ITG)/trapped electron mode turbulence, is studied. Two neutral beam injection (NBI) heated JET discharges

Resonant interaction of energetic ions with bulk-ion plasma micro-turbulence

A significant fast ion-induced stabilization is observed in linear and nonlinear GENE gyrokinetic simulations, which can be attributed to a resonant interaction between energetic particles and the

New High-Confinement Regime with Fast Ions in the Core of Fusion Plasmas.

The F-ATB (fast ion-induced anomalous transport barrier) is characterized by a full suppression of the turbulent transport-caused by strongly sheared, axisymmetric E×B flows-and an increase of the neoclassical counterpart, albeit keeping the overall fluxes at significantly reduced levels.

En Route to High-Performance Discharges: Insights and Guidance from High-Realism Gyrokinetics

Comprehensive state-of-the-art validation studies with AUG fluctuation measurements will be presented and nonlocal studies will be shown confirming that the level of stabilization and threshold values for transitions between electromagnetic micro-instabilities, like ion temperature gradient driven and kinetic ballooning modes, may be affected by nonlocal effects.

Turbulence suppression by energetic particles: a sensitivity-driven dimension-adaptive sparse grid framework for discharge optimization

A newly developed sensitivity-driven approach is employed to study the role of energetic particles in suppressing turbulence-inducing micro-instabilities for a set of realistic JET-like cases with

Gyrokinetic modelling of the Alfvén mode activity in ASDEX Upgrade with an isotropic slowing-down fast-particle distribution

In the present paper, the evolution of the Alfvén modes (AMs) is studied in a realistic ASDEX Upgrade equilibrium by analyzing the results of simulations with the global, electromagnetic, gyrokinetic

Light impurity transport in tokamaks: on the impact of neutral beam fast ions

Previous studies (e.g. (Kappatou 2019 Nucl. Fusion 59 056014)) have shown that discrepancies exist between experimental and modelled light impurity peaking in specific regimes. In particular, in NBI

References

SHOWING 1-10 OF 33 REFERENCES

Non-Maxwellian background effects in gyrokinetic simulations with GENE

The interaction between fast particles and core turbulence has been established as a central issue for a tokamak reactor. Recent results predict significant enhancement of electromagnetic

Fast-ion stabilization of tokamak plasma turbulence

A significant reduction of the turbulence-induced anomalous heat transport has been observed in recent studies of magnetically confined plasmas in the presence of a significant fast-ion fractions.

Ion temperature profile stiffness: non-linear gyrokinetic simulations and comparison with experiment

Recent experimental observations at JET show evidence of reduced ion temperature profile stiffness. An extensive set of nonlinear gyrokinetic simulations are performed based on the experimental

Turbulent transport of alpha particles in reactor plasmas

A systematic study of the behavior of energetic ions in reactor plasmas is presented. Using self-consistent gyrokinetic simulations, in concert with an analytic asymptotic theory, it is found that

Turbulent transport of beam ions

The radial redistribution of energetic ions by background turbulence is investigated by means of linear and nonlinear gyrokinetic simulations with the GENE code [T. Dannert and F. Jenko, Phys.

Global anomalous transport of ICRH- and NBI-heated fast ions

By taking advantage of the trace approximation, one can gain an enormous computational advantage when solving for the global turbulent transport of impurities. In particular, this makes feasible the

Quasi-linear ion distribution function during ion cyclotron heating in tokamaks

A new, very fast code, SSFPQL, which solves the steady state quasi-linear kinetic equation describing the ion distribution function during ion cyclotron heating in two velocity variables has been

Progress in GYRO validation studies of DIII-D H-mode plasmas

The need for a validated predictive capability of turbulent transport in ITER is now widely recognized. However, to date most validation studies of nonlinear codes such as GYRO (Candy and Waltz 2003

Energetic ion distribution resulting from neutral beam injection in tokamaks

  • J. Gaffey
  • Physics
    Journal of Plasma Physics
  • 1976
The Fokker-Planck equation is studied for an energetic ion beam injected into a magnetized plasma consisting of Maxwellian ions and electrons with υthi ≪υb≪ υthe. The time evolution of the fast ion