Particle drift, diffusion, and acceleration at shocks
Abstract
The gradient and curvature drifts implicit in change of the ambient magnetic field at a hydromagnetic shock wave are incorporated into the diffusive theory of shock acceleration of charged particles. The conventional jump condition at the shock is modified by a term incorporating the large drift along the shock plane. This term vanished identically for onedimensional systems, but must be included in general for shocks which are finite in transverse extent or which have transverse structure. It is found that the effect of the drift is such that the transverse drift rate is proportional to the acceleration rate, and for perpendicular shocks is exactly equal to the rate of change of energy in the V x B electric field observed in the shock frame. This establishes a connection with the 'shock drift' models which neglect diffusion.
 Publication:

The Astrophysical Journal
 Pub Date:
 April 1982
 DOI:
 10.1086/159870
 Bibcode:
 1982ApJ...255..716J
 Keywords:

 Charged Particles;
 Magnetohydrodynamic Waves;
 Particle Acceleration;
 Particle Diffusion;
 Particle Motion;
 Shock Wave Interaction;
 Drift Rate;
 Electric Field Strength;
 Energy Transfer;
 Particle Energy;
 Plasma Acceleration;
 Transverse Waves;
 Astrophysics