  In-situ observations of the solar wind (SW) plasma from 0.29 to 1AU show that
the protons and alpha particles are often non-Maxwellian, with evidence of
kinetic instabilities, temperature anisotropies, differential ion streaming,
and associated magnetic fluctuations spectra. The kinetic instabilities in the
SW multi-ion plasma can lead to preferential heating of alpha particles and the
dissipation of magnetic fluctuation energy, affecting the kinetic and global
properties of the SW. Using for the first time a three-dimensional hybrid
model, where ions are modeled as particle using the Particle-In-Cell (PIC)
method and electrons are treated as fluid, we study the onset, nonlinear
evolution and dissipation of ion kinetic instabilities. The
Alfven/ion-cyclotron, and the ion drift instabilities are modeled in the region
close to the Sun (~10R_s). Solar wind expansion is incorporated in the model.
The model produces self-consistent non-Maxwellian velocity distribution
functions (VDFs) of unstable ion populations, the associated temperature
anisotropies, and wave spectra for several typical SW instability cases in the
nonlinear growth and saturation stage of the instabilities. The 3D hybrid
modeling of the multi-ion SW plasma could be used to study the SW acceleration
region close to the Sun that will be explored by the Parker Solar Probe
mission.
