A quasi-one-dimensional velocity regime of super-thermal electron stream propagation through the solar corona
✍ Scribed by B. N. Levin
- Publisher
- Springer
- Year
- 1984
- Tongue
- English
- Weight
- 654 KB
- Volume
- 92
- Category
- Article
- ISSN
- 0038-0938
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✦ Synopsis
The propagation of an inhomogencous, stream of fast electrons through the corona -the type Ill radio burst source -is considered. It is shown, that the angular spectrum width of plasma waves excited by the stream is defined both by Landau damping by particles of the diffuse component and by damping (in the region of large phase velocities) by particles of the stream itself having large pitch angles. The regime of quasi-one-dimensional diffusion in the velocity space is realized only in the presence of a sufficiently dense diffnse component of super-thermal particles and only for a sufficiently large inhomogeneity scale of the stream. A large scale of the stream space profile is formed, evidently, close to the region of injection of super-thermal particles. It is the result of 'stripping" of part of the electrons from the stream fl'ont to its slower part due to essential non-one-dimensionality of the particle diffusion in velocity space.
Rcsults obtained may explain, in particular, the evolution of a stream particle angular spectrum tn the generation region of type Ill radio bursts observed by spacecrafts (Lin et al., 1981). For the relatively low energetic part of the stream, the oblique plasma wave stabilization by a diffuse component results in a quasi-one-dimensional regime of diffusion. The latter conserves the beam-like structure of this part of the stream.