Nonlinear collisionless damping of Weibel turbulence in relativistic blast waves
Abstract
The Weibel/filamentation instability is known to play a key role in the physics of weakly magnetized collisionless shock waves. From the point of view of high energy astrophysics, this instability also plays a crucial role because its development in the shock precursor populates the downstream with a smallscale magnetostatic turbulence which shapes the acceleration and radiative processes of suprathermal particles. The present work discusses the physics of the dissipation of this Weibelgenerated turbulence downstream of relativistic collisionless shock waves. It calculates explicitly the firstorder nonlinear terms associated to the diffusive nature of the particle trajectories. These corrections are found to systematically increase the damping rate, assuming that the scattering length remains larger than the coherence length of the magnetic fluctuations. The relevance of such corrections is discussed in a broader astrophysical perspective, in particular regarding the physics of the external relativistic shock wave of a gammaray burst.
 Publication:

Journal of Plasma Physics
 Pub Date:
 January 2015
 DOI:
 10.1017/S0022377814000920
 arXiv:
 arXiv:1410.0146
 Bibcode:
 2015JPlPh..81a4501L
 Keywords:

 Physics  Plasma Physics;
 Astrophysics  High Energy Astrophysical Phenomena
 EPrint:
 21 pages, 2 figures