ABSTRACT

206Alfvénic turbulence has been detected by Comet Halley at spacecrafts Giotto and Vega and by Comet Giacobini-Zinner at International Cometary Explorer (ICE). We have studied the KAW instability driven by field aligned drifts of solar wind electrons (se), and protons (H) in a cometary pair-ion plasma consisting of cometary electrons (ce), positively and negatively charged oxygen ions, with each species being modeled by a drifting ring distribution [with Vdce = VdO+ = VdO = 0 and VdH = Vdse].

In the low frequency regime, the dispersion relation is a polynomial equation of order four. We find that the growth rate increases with increasing drift velocities of hydrogen. The growth rate which increases with increasing hydrogen densities, decreases with increasing oxygen densities.