Ambipolar diffusion-driven tearing instability in a steepening background magnetic field

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/27903

Title:	Ambipolar diffusion-driven tearing instability in a steepening background magnetic field
Authors:	Chiueh,T
Contributors:	天文研究所
Date:	1998
Issue Date:	2010-06-29 19:35:50 (UTC+8)
Publisher:	中央大學
Abstract:	Tearing instability is shown to be greatly enhanced by ambipolar diffusion near the locations where two-dimensional magnetic fields reverse signs. The growth time is found to be on the order of the ambipolar diffusion timescale, independent of electrical resistivity. Consistent with the earlier works, the enhancement in the reconnection of field lines indeed arises from the development of a singular current perturbation. Such magnetic reconnection is driven by the steepening effect of ambipolar diffusion on the magnetic fields near the held-reversal lines. Although the background magnetic fields are evolving on a similar timescale as the perturbations, we show that magnetic reconnection proceeds substantially faster than the steepening of the background fields. In contrast to the conventional tearing instabilities in three dimensions, where the magnetic reconnection occurs only in the flux surfaces that contain the free energy, a positive Delta', the three-dimensional extension of this new tearing instability can occur only in regions where the Lorentz force reverses the sign. This report outlines how the three-dimensional reconnection may proceed in a similar fashion as the two-dimensional counterpart does.
Relation:	ASTROPHYSICAL JOURNAL
Appears in Collections:	[Graduate Institute of Astronomy] journal & Dissertation

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	468	View/Open

社群 sharing

Loading...