26 June 2011 to 1 July 2011
Montpellier, France
Europe/Paris timezone

Magnetic turbulence in the shock precursor and CR acceleration

29 Jun 2011, 11:20
35m
Main amphitheater (Universe)

Main amphitheater

Universe

Speaker

Dr Beresnyak Andrey (Ruhr University Bochum)

Description

We overview recent progress on small-scale dynamo and apply the results to the the problem of nonlinear shock acceleration in which particle mean free paths in front of the shock are greatly reduced due to magnetic fields in the shock precursor which are generated through small-scale dynamo in the density gradient's-induced turbulence. Previous DSA models considered magnetic fields amplified through cosmic ray streaming instabilities either by way of individual particles scattering in the magnetic fields, or by macroscopic electric currents associated with large-scale cosmic ray streaming. The small-scale dynamo mechanism provides fast growth and is very generic. For supernovae shocks this mechanism is estimated to generate upstream magnetic fields that are sufficient for accelerating cosmic rays up to around 10^16 eV.

Presentation Materials