相关论文: Alpha particle driven Alfv\'enic instabilities in …
The waves generated by high-energy proton and alpha particles streaming from solar flares into regions of colder plasma are explored using particle-in-cell simulations. Initial distribution functions for the protons and alphas consist of…
Nonlinear wave-wave coupling constitutes an important route for the turbulence spectrum evolution in both space and laboratory plasmas. For example, in a reactor relevant fusion plasma, a rich spectrum of symmetry breaking shear Alfv\'en…
Previous studies have shown that the observed temperature anisotropies of protons and alpha particles in the solar wind are constrained by theoretical thresholds for pressure-anisotropy-driven instabilities such as the…
We present three-dimensional, hybrid-kinetic numerical simulations of driven Alfv\'{e}n-wave turbulence of relevance to the collisionless near-Earth solar wind. Special attention is paid to the spectral transition that occurs near the…
In this work, the gyrokinetic eigenvalue code LIGKA, the drift-kinetic/MHD hybrid code HMGC and the gyrokinetic full-f code TRIMEG-GKX are employed to study the mode structure details of Reversed Shear Alfv\'en Eigenmodes (RSAEs). Using the…
Using the orbit-following code ASCOT, we model alpha particle transport in ITER under the influence of ELM control coils (ECCs), toroidal field ripple, and test blanket modules, with emphasis on how the plasma response (PR) modifies the…
We propose a new electromagnetic-emission mechanism in magnetized, force-free plasma, which is driven by the evolution of the underlying dynamic spacetime. In particular, the emission power and angular distribution of the emitted…
Burning plasma performance, transport, and the effect of hydrogen isotope on confinement has been predicted for ITER baseline scenario (IBS) conditions using nonlinear gyrokinetic profile predictions. Accelerated by surrogate modeling [P.…
Both observations and numerical simulations suggest that Alfvenic waves may carry sufficient energy to sustain the hot temperatures of the solar atmospheric plasma. However, the thermalization of wave energy is inefficient unless very short…
A generation mechanism of super Alfv\'{e}nic (SPA) waves in multi-ion species plasma is proposed and the associated heavy ion acceleration process is discussed. The SPA waves are thought to play important roles in particle acceleration…
Solar flares involve complex processes that are coupled and span a wide range of temporal, spatial, and energy scales. Modeling such processes self-consistently has been a challenge in the past. Here we present results from simulations that…
We present first-principles numerical calculations of the depolarization rate of spin-polarized deuterium and tritium nuclei in realistic tokamak plasmas, driven by resonant interactions with plasma waves. Backed up by first-of-a-kind…
Disruption-generated runaway electrons (RE) present an outstanding issue for ITER. The predictive computational studies of RE generation rely on orbit-averaged computations and, as such, they lack the effects from the magnetic field…
In space and astrophysical plasmas, violent events or instabilities inject energy into turbulent motions at large scales. Nonlinear interactions among the turbulent fluctuations drive a cascade of energy to small perpendicular scales at…
The evolution of Alfven turbulence due to three-wave interactions is discussed using kinetic theory for a collisionless, thermal plasma. There are three low-frequency modes, analogous to the three modes of compressible MHD. When only Alfven…
Transverse electromagnetic and electrostatic plasma wave modes propagating along a background magnetic field $\vec{B}_0$ are independent according to linear kinetic theory. However, resonant interactions and energy exchange between waves…
Counterpropagating Alfv\'en waves are ubiquitously observed in many astrophysical environments, such as a star surface and a planetary foreshock. We discuss an efficient particle acceleration mechanism in two counterpropagating circularly…
Using one-dimensional numerical simulations, we study the elementary process of Alfv\'{e}n wave reflection in a uniform medium, including nonlinear effects. In the linear regime, Alfv\'{e}n wave reflection is triggered only by the…
The cascade of kinetic Alfv\'en waves (KAWs) at the sub-ion scales in the solar wind is numerically simulated using a fluid approach that retains ion and electron Landau damping, together with ion finite Larmor radius corrections. Assuming…
It is shown that a three-dimensional (3D) modified-kinetic Alfv\'en waves (m-KAWs) can propagate in the form of Alfv\'enic tornadoes characterized by plasma density whirls or magnetic flux ropes carrying orbital angular momentum (OAM). By…