Pitch Angle Sca2tering of Cometary Ions into Monospherical and Bispherical Distributions

Low frequency magnetic fluctuations generated by solar wind/cometary ion distributions cause pitch-angle scattering of cometary ions. The nature of this pitch angle scattering is examined by means of one-dimensional hybrid simulations, in which newborn ions are created at a constant rate, and for various injection angles, o•, relative to the magnetic field. Pitch angie scattering in the quasiperpendicular regime (o•>60 ø) results in a bispherical velocity distribution while in the quasi-parallel regime (0_<or<60ø), pitch angle scattering can result in either a mono or bispherical distribution depending on the injection angle and initial beam velocity.