Magnetic guide field generation in thin collisionless current sheets

Abstract

In thin ($\Delta<$ few $\lambda_i$) collisionless current sheets in a space plasma like the magnetospheric tail or magnetopause current layer, magnetic fields can grow {from thermal fluctuation level by the action of the non-magnetic Weibel instability \citep{weibel1959}. }The instability is driven by the counter-streaming electron inflow from the `ion diffusion' (ion inertial Hall) region into the inner current (electron inertial) region after thermalisation by the two-stream instability. Under magnetospheric tail conditions it takes $\sim$ 50 e-folding times ($\sim$ 100 s) for the Weibel field to reach observable amplitudes $|{\bf b}_{\,\rm W}|\sim 1$ nT. In counter-streaming inflows these fields are of guide field type.

Further Information
www.ann-geophys.net/28/789/2010
BibTeX
@article{id1539,
  author = {Baumjohann, W. and Nakamura, R. and Treumann, R. A.},
  journal = {Annales Geophysicae},
  language = {en},
  note = {Refereed and substantially re-written Journal version with alphabetically listed authors},
  pages = {789-793},
  title = {Magnetic guide field generation in thin collisionless current sheets},
  url = {www.ann-geophys.net/28/789/2010},
  volume = {28},
  year = {2010},
}
EndNote
%O Journal Article
%A Baumjohann, W.
%A Nakamura, R.
%A Treumann, R. A.
%J Annales Geophysicae
%G en
%O Refereed and substantially re-written Journal version with alphabetically listed authors
%P 789-793
%T Magnetic guide field generation in thin collisionless current sheets
%U www.ann-geophys.net/28/789/2010
%V 28
%D 2010