Document Type

Article

Publication Date

7-2013

Publication Title

Annales Geophysicae

Publisher

Copernicus Publications

Abstract

We have investigated the generation of magnetic fields associated with velocity shear between an unmagne-tized relativistic jet and an unmagnetized sheath plasma. We have examined the strong magnetic fields generated by ki-netic shear (Kelvin–Helmholtz) instabilities. Compared to the previous studies using counter-streaming performed by Alves et al. (2012), the structure of the kinetic Kelvin– Helmholtz instability (KKHI) of our jet-sheath configura-tion is slightly different, even for the global evolution of the strong transverse magnetic field. In our simulations the major components of growing modes are the electric field Ez, perpendicular to the flow boundary, and the magnetic field By, transverse to the flow direction. After the By com-ponent is excited, an induced electric field Ex, parallel to the flow direction, becomes significant. However, other field components remain small. We find that the structure and growth rate of KKHI with mass ratios mi/me = 1836 and mi/me = 20 are similar. In our simulations saturation in the nonlinear stage is not as clear as in counter-streaming cases.

Comments

This work is distributed under the Creative Commons Attribution 3.0 License.

The published version can be found here: http://www.ann-geophys.net/31/1535/2013/angeo-31-1535-2013.html

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