Doing numerical calculations of axially symmetric force-flee fields, have noticed that there seem to be no solutions if the toroidal component of the field exceeds a certain limit. In the present paper this problem is reexamined in the approximation of a plane stellar surface using a very simple an
The stability of force-free magnetic fields with cylindrical symmetry in the context of solar flares
โ Scribed by Ulrich Anzer
- Publisher
- Springer
- Year
- 1968
- Tongue
- English
- Weight
- 789 KB
- Volume
- 3
- Category
- Article
- ISSN
- 0038-0938
No coin nor oath required. For personal study only.
โฆ Synopsis
The problem of the accumulation and storage of the energy released in solar flares is discussed; it is propose d that convective energy of the photosphere is transformed into magnetic energy of the chromosphere and corona. The consequences of a large ratio of magnetic pressure to gas pressure are investigated. In this case the field must be approximately force-free. The only suitable force-free fields which allow an analytical treatment are those of cylindrical symmetry. The stability of these fields is studied with the energy principle. It is shown that they are always unstable due to kink type instabilities. The shape of the unstable perturbations is described in detail and an upper limit for their amplitude is estimated. The consequences for the proposed mechanism of energy storage are briefly discussed.
๐ SIMILAR VOLUMES
The condition of stability obtained earlier is generalized for the case of arbitrary force-free fields (f.f.f.). It is shown that the configurations are stable, if the ratio of the current to the field and its gradient are small enough.