Electromagnetic turbulence suppression by energetic particle driven modes

Abstract

In recent years, a strong reduction of plasma turbulence in the presence of energetic particles has been reported in a number of magnetic confinement experiments and corresponding gyrokinetic simulations. While highly relevant to performance predictions for burning plasmas, an explanation for this primarily nonlinear effect has remained elusive so far. A thorough analysis finds that linearly marginally stable energetic particle driven modes are excited nonlinearly, depleting the energy content of the turbulence and acting as an additional catalyst for energy transfer to zonal modes (the dominant turbulence saturation channel). Respective signatures are found in a number of simulations for different JET and ASDEX Upgrade discharges with reduced transport levels attributed to energetic ion effects.

References in corpus (7)

• Breaking an Abelian gauge symmetry near a black hole horizon
• Nonlinear stabilization of tokamak microturbulence by fast ions
• Electromagnetic stabilization of tokamak microturbulence in a high-$\beta$ regime
• Nonlinear entropy transfer via zonal flows in gyrokinetic plasma turbulence
• Non-Maxwellian fast particle effects in gyrokinetic GENE simulations
• Validating modelling assumptions of alpha particles in electrostatic turbulence
• Phase transitions in AdS soliton spacetime through marginally stable modes

Cited by in corpus (9)

• Turbulence suppression by energetic particle effects in modern optimized stellarators
• Global gyrokinetic simulations of ASDEX Upgrade up to the transport time-scale with GENE-Tango
• Gyrokinetic particle-in-cell simulations of electromagnetic turbulence in the presence of fast particles and global modes
• Data-driven low-fidelity models for multi-fidelity Monte Carlo sampling in plasma micro-turbulence analysis
• Core transport barriers induced by fast ions in global gyrokinetic GENE simulations
• Predictions of improved confinement in SPARC via energetic particle turbulence stabilization
• Turbulence suppression by energetic particles: A sensitivity-driven dimension-adaptive sparse grid framework for discharge optimization
• Towards enhanced performance in fusion plasmas via turbulence suppression by MeV ions
• Numerics and computation in gyrokinetic simulations of electromagnetic turbulence with global particle-in-cell codes