Toroidal Distributions in the Polar Wind Plasma
Publication Type
Original research
  • Naji Qatanani
  • M. Abu Issa
  • I. Barghouthi

The energization of charged particles, due to interaction with electromagnetic turbulence, has an important influence on the plasma outflow in space. The effect of wave-particle interaction (WPI) on O+ and H+ velocity distributions in the polar wind was investigated by using Monte Carlo method. The Monte Carlo simulation included the effect of WPI, gravity, polarization electrostatic field, and the divergence of geomagnetic field within the simulation tube (1.7-10 earth radii, Re) as the ions are heated due to WPI and move to higher altitudes, the ion's Larmor radius aL may become comparable to the perpendicular wave length λ⊥ of the electromagnetic turbulence. As the ratio aL/λ⊥ becomes ≥1, the quasi-linear perpendicular diffusion coefficient becomes velocity dependent, the heating rate becomes self-limited and the ion ditribution displays toroidal features. This result is consistent with observations of or toroidal distribution in the auroral region.

Indian Journal of Physics, 01/2003; 77(6):621 – 624
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