Diese Seite ist aus Gründen der Barrierefreiheit optimiert für aktuelle Browser. Sollten Sie einen älteren Browser verwenden, kann es zu Einschränkungen der Darstellung und Benutzbarkeit der Website kommen!
Geophysics Homepage
Search:
Log in
print

Magnetic guide field generation in thin collisionless current sheets

Treumann, R. A., R. Nakamura, and W. Baumjohann (2009), Magnetic guide field generation in thin collisionless current sheets, arXiv:0903.0334, 9, pdf-LaTex manuscript, 9 pages, 2 figure, theoretical: Weibel instability in thin 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 from where the ambient magnetic fields are excluded when released by the inflowing electrons which become non-magnetic on scales smaller than the electron gyroradius and $<$ few $\lambda_e$. It is shown that under magnetospheric tail conditions it takes $\sim$ 20-40 e-folding times ($\sim$ 10-20 s) for the Weibel field to reach observable amplitudes $|{\bf b}_{\rm W}|\sim 1$ nT. In counter-streaming inflows these fields are predominantly of guide field type. This is of interest in magnetic guide field reconnection. Guide fields are known to possibly providing the conditions required for the onset of bursty reconnection \citep {drake2006,pritchett2005a,pritchett2006a,cassak2007}. In non-symmetric inflows the Weibel field might itself evolve a component normal to the current sheet which could also contribute to reconnection onset.
Further information
BibTeX
@article{id1537,
  author = {R. A. Treumann and R. Nakamura and W. Baumjohann},
  journal = {arXiv:0903.0334},
  note = {pdf-LaTex manuscript, 9 pages, 2 figure, theoretical: Weibel instability in thin current sheets},
  pages = {9},
  title = {{Magnetic guide field generation in thin collisionless current sheets}},
  year = {2009},
  url = {http://adsabs.harvard.edu/abs/2009arXiv0903.0334T},
}
EndNote
%0 Journal Article
%A Treumann, R. A.
%A Nakamura, R.
%A Baumjohann, W.
%D 2009
%J arXiv:0903.0334
%P 9
%Z pdf-LaTex manuscript, 9 pages, 2 figure, theoretical: Weibel instability in thin current sheets
%T Magnetic guide field generation in thin collisionless current sheets
%U http://adsabs.harvard.edu/abs/2009arXiv0903.0334T
ImprintPrivacy PolicyContact
Printed 25. Aug 2019 08:42