Conveners
Effects of Energetic Particles in Magnetic Confinement Fusion Devices
- Taina Kurki-Suonio (Aalto University)
Abstract:
JET deuterium experiments in an advanced tokamak scenario with an internal transport barrier (ITB) exhibit unstable electromagnetic (EM) perturbations in the sub-TAE frequency range. In JET pulse number (JPN) 92054, a high-beta plasma ($\beta_N = \beta_T B_T a / I_P \sim 4.38 [\%Tm/MA]$) with high power neutral beam injection (NBI), $P_{NBI} = 25.1 MW$, contained EM...
Based on the experimental parameters in HL-2A tokamak, the linear stability and nonlinear dynamics of BAE with reversed safety factor $q$ profile are investigated by using kinetic-MHD code M3D-K. It is found that the ($m/n=3/2$) BAE is excited by co-passing energetic ions with $q_{min}=1.5$ in linear simulation, and the mode frequency is consistent with experimental meuasurement. The...
Ion cyclotron resonance frequency (ICRF) heating has been chosen as one of the fundamental auxiliary heating systems in many present-day fusion devices, as well as the upcoming ITER. Energetic ions generated by ICRF heating with energies up to several hundred-keV or several MeV can drive a variety of Alfven eigenmodes, such as reversed-shear, toroidal and ellipticity Alfven eigenmodes (RSAE,...
Edge localized modes (ELMs) are periodic magnetohydrodynamic (MHD) instabilities driven by sharp pressure gradients and current densities at the plasma boundary that will likely lead to transient, and intolerable, energy and particle losses in ITER. Although the ELM nature is still under intense investigation, their behavior and their consequences in a burning plasma with a significant...
In recent years, there has been significant progress with global electromagnetic gyrokinetic codes in modelling Alfvén Eigenmodes (AEs) and other energetic particle (EP) driven instabilities in realistic equilibria, for example, simulations with the gyrokinetic code ORB5 [1] of Energetic Particle Modes (EPMs) and Energetic-particle-driven Geodesic Acoustic Modes (EGAMs) in ASDEX Upgrade (AUG)...
Tungsten accumulation is one of the main challenges for successful operation of ITER and future reactors. For this reason, various techniques have been developed recently in order to mitigate such accumulation. One of such methods is the application of wave heating, in particular electron cyclotron resonance heating (ECRH) deposited close to the plasma center.
Recent 3D equilibrium...
Verification and validation of the internal kink instability in tokamak have been performed for both gyrokinetic (GTC) and kinetic-MHD codes (GAM-solver, M3D-C1-K, NOVA, XTOR-K). Using realistic magnetic geometry and plasma profiles from the same equilibrium reconstruction of the DIII-D shot #141216, these codes exhibit excellent agreements for the growth rate and mode structure of the n=1...
Recent DIII-D experiments show that sawteeth can be strongly affected by anisotropic fast ions from Neutral Beam Injection (NBI) in both negative and positive triangularity plasma configurations. Fast ions from co-current NBI are stabilizing for the sawtooth stability, resulting in longer sawtooth periods. On the other hand, fast ions from counter-current NBI are destabilizing, leading to...
The D-T fusion cross-section in magnetically confined plasmas is increased by 50% when the spins of both nuclei are polarized along the magnetic field[1], offering promise for a significant increase in fusion energy output with no additional requirement on plasma confinement. Theoretically [1], depolarization mechanisms from field inhomogeneities or collisions are weak in the core of a tokamak...
Linear numerical simulations using FAR3d indicate that negative triangularity (NT) shaping of plasma in DIII-D lowers the growth rate of energetic particle (EP) driven Alfvén eigenmodes (AEs) as compared to the positive triangularity (PT) shaping of plasma [1]. Recently, there is a renewed interest in the NT shaping for its benefits of reduced microturbulence, better thermal confinement and...
