Nonlinear Coupling of Kinetic Alfvén Waves and Ion Acoustic Waves in the Inner Heliosphere  

作　　者：Mani K.Chettri Vivek Shrivastav Rupak Mukherjee Nidhi Gaur R.P.Sharma Hemam D.Singh 

机构地区：[1]Department of Physics,Sikkim University,Gangtok,Sikkim,India [2]DAV Public School,Sector 14,Gurugram,Haryana,India [3]Plasma Simulation Laboratory,Department of Energy Science and Engineering,Indian Institute of Technology Delhi,Delhi,India

出　　处：《Research in Astronomy and Astrophysics》2024年第10期141-158,共18页天文和天体物理学研究（英文版）

基　　金：the University Grants Commission,India for providing a Non-NET fellowship。

摘　　要：We study the nonlinear coupling of kinetic Alfvén waves with ion acoustic waves applicable to the Earth’s radiation belt and near-Sun streamer belt solar wind using dynamical equations in the form of modified Zakharov systems.Numerical simulations show the formation of magnetic field filamentary structures associated with density humps and dips which become turbulent at later times,redistributing the energy to higher wavenumbers.The magnetic power spectra exhibit an inertial range Kolmogorov-like spectral index value of-5/3 for k_(⊥)ρ_(i)<1 followed by a steeper dissipation range spectra with indices~-3 for the radiation belt case and~-4 for the nearSun streamer belt solar wind case,here k_(⊥)andρ_(i)represent the wavevector component perpendicular to the background magnetic field and the ion thermal gyroradius,respectively.Applying quasilinear theory in terms of the Fokker-Planck equation in the region of wavenumber turbulent spectra,we find the particle distribution function flattening in the superthermal tail population which is the signature of particle energization and plasma heating.

关 键 词：Sun:chromosphere Sun:corona Sun:heliosphere 

分 类 号：P182[天文地球—天文学]