Quasilinear Consequences of Turbulent Ion Heating by Magnetic Moment Breaking
arXiv:1812.05021 · doi:10.3847/1538-4357/aaf16d
Abstract
The fast solar wind emerging from coronal holes is likely heated and accelerated by the dissipation of magnetohydrodynamic turbulence, but the specific kinetic mechanism resulting in the perpendicular ion heating required by observations is not understood. A promising mechanism has been proposed by Chandran et al. (2010), which in this paper we call "magnetic moment breaking" (MMB). As currently formulated, MMB dissipation operates only on the ion perpendicular motion, and does not influence their parallel temperature. Thus, the MMB mechanism acting by itself produces coronal hole proton distributions that are unstable to the ion-cyclotron anisotropy instability. This quasilinear instability is expected to operate faster than the nonlinear turbulent cascade, scattering ions into the parallel direction and generating quasi-parallel-propagating ion-cyclotron (IC) waves. To investigate the consequences of this instability on the MMB-heated protons, we construct a homogeneous model for protons with coronal hole properties. Using a simplified version of the resonant cyclotron interaction, we heat the protons by the MMB process and instantaneously scatter them to lower anisotropy while self-consistently generating parallel-propagating IC waves. We present several illustrative cases, finding that the extreme anisotropies implied by the MMB mechanism are limited to reasonable values, but the distinctive shape of the proton distribution derived by Klein & Chandran (2016) is not maintained. We also find that these combined processes can result in somewhat higher particle energization than the MMB heating alone. These quasilinear consequences should follow from any kinetic mechanism that primarily increases the perpendicular ion temperature in a collisionless plasma.
arXiv commentTo be published in The Astrophysical Journal
References in corpus (22)
- Spectrum of magnetohydrodynamic turbulence
- On the Generation, Propagation, and Reflection of Alfven Waves from the Solar Photosphere to the Distant Heliosphere
- Anisotropic scaling of magnetohydrodynamic turbulence
- Perpendicular Ion Heating by Low-Frequency Alfven-Wave Turbulence in the Solar Wind
- A turbulence-driven model for heating and acceleration of the fast wind in coronal holes
- Particle Heating by Alfvenic Turbulence in Hot Accretion Flows
- Nonlinear Dynamics of the Parker Scenario for Coronal Heating
- Power and spectral index anisotropy of the entire inertial range of turbulence in the fast solar wind
- Energy transfer, pressure tensor and heating of kinetic plasma
- Intermittent Dissipation and Local Heating in the Solar Wind
- Three-Dimensional Structure of Solar Wind Turbulence
- Kinetic dissipation and anisotropic heating in a turbulent collisionless plasma
- Spectral scaling laws in MHD turbulence simulations and in the solar wind
- Alfven Wave Turbulence and Perpendicular Ion Temperatures in Coronal Holes
- Turbulence in the sub-Alfvénic solar wind driven by reflection of low-frequency Alfvén waves
- Improved Constraints on the Preferential Heating and Acceleration of Oxygen Ions in the Extended Solar Corona
- Observational Test of Stochastic Heating in Low- Fast Solar Wind Streams
- Ensemble Simulations of Proton Heating in the Solar Wind via Turbulence and Ion Cyclotron Resonance
- Perpendicular Ion Heating by Reduced Magnetohydrodynamic Turbulence
- Evolution of The Proton Velocity Distribution due to Stochastic Heating in the Near-Sun Solar Wind
- Self-Consistent Ion Cyclotron Anisotropy-Beta Relation for Solar Wind Protons
- A Self-Consistent Marginally Stable State for Parallel Ion Cyclotron Waves