Freiburg 2008 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 5: Astrophysics - Poster Session
EP 5.1: Poster
Montag, 3. März 2008, 17:30–19:00, Vorraum KGI-Aula
Linear and Nonlinear Modes in Collisionless Unmagnetized Plasmas — •Urs Schaefer-Rolffs1, Ian Lerche2, and Reinhard Schlickeiser1 — 1Institut für theoretische Physik IV, Ruhr-Universität Bochum — 2Institut für Geowissenschaften, Martin-Luther-Universität Halle
This poster reports a work that is divided into two parts. In the first section we want to enlighten some general properties of the Weibel instability, while the second part will present a new type of solitary waves in such plasmas.
The Weibel instability was established by Erich S. Weibel in 1959 [1]. Unlike to many other plasma waves, the Weibel modes do not require a native magnetic field, i.e. this instability can set in in unmagnetized plasmas, too. Thus it is possible - and this is one main inducement to investigate it - to create magnetic fields with this mechanism. Various authors have explored this instability up to now, following the same scheme: take the dispersion relation, pick one distribution function and study. As we are interested in general results we chose a different way by screening the instability for conclusions without prescribing a distribution. This results will be presented.
The solitary waves were motivated by observation of isolated modes while researching the Weibel modes. These isolated modes allude us to solitons, thus we tried and were able to derive a wave equation. The possible usefulness of these solitary waves are proved by applying them to the case of the radiation of relativistic jets.
[1] E.S. Weibel, Phys. Rev. Lett., 2, 83f (1959)