The Structure of Hydromagnetic Shock Waves

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چکیده

Es werden Wellen in einem quasi-neutralen Gas untersucht, das Ionen und Elektronen enthält und genügend kalt ist, so daß die thermischen Bewegungen vernachlässigt werden können. Außerdem werden Zusammenstöße zwischen den Teilchen vernachlässigt, jedoch nicht die Trägheitseffekte des elektrischen Stromes. Die nicht-linearen Gleichungen für unendlich ausgedehnte, ebene Kompressionswellen, die sich senkrecht zu einem homogenen Magnetfeld mit ungeänderter Form und Geschwindigkeit ausbreiten, werden auf eine einzige Diff.-Gl. 2. Ordnung für das Magnetfeld (oder für die Verschiebung der Teilchen senkrecht zur Ausbreitungsrichtung) zurückgeführt, vorausgesetzt, daß die Teilchenbahnen keine Schleifen bilden. Diese Diff.-Gl. wird exakt durch elliptische Funktionen gelöst. Verschiedene Kurven, die durch numerische Integration erhalten wurden, beschreiben die wesentlichen Eigenschaften der Lösungen. Außerdem werden Potenzreihen-Entwicklungen in der Amplitude a angegeben, wobei der Fehler in der Ordnung a4 ist. Die Lösungen sind entweder periodische Wellenzüge oder Einzelwellen. Alle Lösungen sind symmetrisch um die Maxima und Minima der magnetischen Feldstärke. Die Wellenlängen sind von der Größenordnung des Gyrationsradius. Die Geschwindigkeiten erstreckten sich vom Wert Null bis zum doppelten der ALFvEN-Geschwindigkeit.

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تاریخ انتشار 2012