Pa. Isenberg et al., The kinetic shell model of coronal heating and acceleration by ion cyclotron waves 1. Outward propagating waves, J GEO R-S P, 106(A4), 2001, pp. 5649-5660
We introduce a new kinetic treatment of the heating of the magnetically ope
n solar corona and the acceleration of the fast solar wind by the cyclotron
resonant interaction of coronal protons with ion cyclotron waves. In this
"kinetic shell" formalism we approximate the evolution of the collisionless
coronal proton distribution by the assumption that the pitch angle diffusi
on due to the resonant ion cyclotron waves is much faster than the other pr
ocesses taking place. Under this assumption the resonant protons uniformly
populate velocity space surfaces, or shells, of constant energy in the fram
e moving with the wave phase speed. These resonant shells then evolve slowl
y in response to the nonresonant large-scale forces in the system. For this
initial demonstration of the kinetic shell concept, we additionally take t
he resonant waves to be solely outward propagating and dispersionless. In t
his case the resonant shells are spherical sections in velocity space which
are confined to the sunward half of the proton distribution. We then calcu
late the radial evolution of collisionless protons in a coronal hole using
this simplified system, which also includes the effects of gravity, the cha
rge-separation electric field, and the mirror force. We find that a fast so
lar wind can be generated by this process using reasonable values of the ph
ysical parameters. However, we also prove that the proton distribution gene
rated by the interaction with only outward propagating waves will necessari
ly be unstable to the generation of inward propagating waves. Thus this ill
ustrative calculation is incomplete and will have to be extended to include
waves in both propagation directions.