ITB formation due to energetic particles. The performance of present-day and future fusion devices is largely determined by turbulent transport generated by plasma turbulence. Any mechanisms able to reduce the overall radial propagation of energy and particles is, therefore, crucial in view of scenario optimization. This contribution presents numerical results of turbulence suppression by...
In the study of burning plasmas it is important to understand multi-scale interactions between energetic-particle-driven MHD mode and drift-wave turbulence for establishing good confinement of both energetic particles and bulk plasmas simultaneously. We investigate nonlinear multi-scale interactions between TAE, which is unstable at low $n$, and drift-wave turbulence, which is driven by...
Tokamak discharges with internal transport barrier (ITB) offer compelling features needed for steady state operation of burning plasmas for its improved energy confinement and high bootstrap current associated with large pressure gradient. To develop a stable ITB plasma usable for fusion reactors, it requires a deep physics understanding of ITB formation and its profile control. This paper...
For over three decades, the observation of rapid core confinement improvement upon favourable modifications of edge operating conditions has been a nagging source of puzzlement for experimentalists investigating conditions for a lasting source of fusion energy in tokamaks. The transport properties of drift-wave turbulence and the interaction of the confined plasma with its material boundaries...
This is the first report of spontaneous Internal Transport Barrier (ITB) formation in reversed magnetic shear plasmas by full-$f$ gyrokinetic simulations with kinetic electrons. We found that (1) a strong mean $E_r$ shear is formed near $q_{min}$ region in flux-driven Ion Temperature Gradient (ITG) turbulence, leading to spontaneous reduction of ion turbulent thermal diffusivity, while it is...
