Proton core-beam system in the expanding solar wind: Hybrid simulations

摘要: [1] Results of a two-dimensional hybrid expanding box simulation proton beam-core system in the solar wind are presented. The expansion with strictly radial magnetic field leads to decrease ratio between perpendicular and parallel temperatures as well an increase differential velocity local Alfven creating free energy for many different instabilities. is indeed most time marginally stable respect magnetosonic, oblique Alfven, cyclotron fire hose instabilities which determine evolution counteracting some effects interacting each other. Nonlinear these large modifications distribution function. beam core protons slowed other heated, at later stages two populations not clearly distinguishable. On macroscopic level cause departures from double adiabatic prediction leading efficient isotropization effective agreement Helios observations.