Self-regulation of energetic solar wind plasma outflows

Within this project we will for the first time address the unknown implications of the fast winds in key processes like kinetic instabilities, which, in the absence of collisions, should counterbalance the adiabatic expansion and magnetic focusing, and explain the observed limits of the temperature anisotropy of plasma particles. Fast coronal outflows are an important manifestation of the solar wind that provides clues on the origin of the energetic events with impact on space weather. The novel element is the employment of realistic models for the velocity distribution functions which combine a thermal core, a suprathermal halo, and a drifting strahl. Such advanced models will enable us to study in unprecedented detail the interplay of these components and validate a local scenario for the origin of space plasma fluctuations induced/stimulated self-consistently by the temperature anisotropy of these populations. The proposed research project is not only theoretical, but it has important applicative components, intending to provide a physical explanation for the confinement of the fast solar wind plasma to small temperature anisotropies, addressing the question whether the free-energy dissipation and pitch-angle scattering by self-generated electromagnetic turbulence are effective or not to establish equipartition between the magnetic field energy density and the kinetic energy density of plasma particles.