A&A 438, 391-402 (2005)
Acceleration of charged particles by gyroresonant surfing at quasi-parallel shocksY. Kuramitsu and V. Krasnoselskikh
Laboratoire Physique et Chimie de l'Environnement, CNRS, 45071 Orléans, France
(Received 29 October 2004 / Accepted 15 March 2005 )
We discuss an acceleration mechanism of charged particles by magnetohydrodynamic (MHD) structures, such as quasi-parallel shocks and short-large amplitude magnetic structures (SLAMS). In the presence of electromagnetic waves and an electrostatic electric field, particles are accelerated efficiently in the perpendicular direction to the background magnetic field by the combination of two effects, the trapping of particles by the wave and the dragging by the electrostatic field to keep the resonance condition. This allows particles to propagate downstream even when they initially have smaller kinetic energy than the potential. We show the fundamental properties of this mechanism, referred to as gyroresonant surfing.
Key words: acceleration of particles -- shock waves -- diffusion
© ESO 2005