Quasilinear diffusion rates of cometary ions
Abstract
The freshly created ions in the upstream region of the cometary bow shock usually form a ringbeam velocity distribution in the solar wind frame of reference. In the present work, the detailed properties of the initial diffusion rates associated with the cometary newborn ions are studied for various physical parameters including the socalled injection angle alpha (that is, the average initial pitch angle associated with the ions) ranging from 0 deg (pure beam distribution) to 90 deg (pure ring distribution). It is shown that initial diffusion rates are strongly dependent upon the angle alpha, such that for alpha = 060 deg (quasiparallel regime) the pitch angle diffusion rate remains relatively small, while for alpha = 6090 deg (quasiperpendicular regime) the diffusion rate increases substantially.
 Publication:

Physics of Fluids B
 Pub Date:
 August 1991
 DOI:
 10.1063/1.859625
 Bibcode:
 1991PhFlB...3.2124Y
 Keywords:

 Comets;
 Computational Astrophysics;
 Diffusion Coefficient;
 Ionic Diffusion;
 Kinetic Equations;
 Method Of Moments;
 Self Consistent Fields;
 Astrophysics