Effects of mirror reflection versus diffusion anisotropy on particle acceleration in oblique shocks

Abstract

Cosmic ray particles are more rapidly accelerated in oblique shocks, with the magnetic field inclined with respect to the shock normal direction, than in parallel shocks, as a result of mirror reflection at the shock surface and slower diffusion in the shock normal direction. We investigate quantitatively how these effects contribute to reducing the acceleration time over the whole range of magnetic field inclinations. It is shown that, for quasi-perpendicular inclination, the mirror effect plays a remarkable role in reducing the acceleration time; whereas, at relatively small inclination, the anisotropic diffusion effect is dominant in reducing that time. These results are important for a detailed understanding of the mechanism of particle acceleration by an oblique shock in space and heliosphereic plasmas.

6 pages, 2 figures

References in corpus (3)

• Magnetic Field Amplification in Tycho and other Shell-type Supernova Remnants
• Confirmation of strong magnetic field amplification and nuclear cosmic ray acceleration in SN 1006
• Proton acceleration beyond 100 EeV by an oblique shock wave in the jet of 3C 273

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