A new coherent radiation mechanism, involving nonlinear interaction of whistler solitons with upperhybrid waves, excited by energetic electrons of energies of 10 keV-100 keV, is proposed for type IV solar bursts of both moving (type IV M) and stationary (type IV S) types. We show that the type IV M
A coherent radiation mechanism for type IV dm radio bursts
โ Scribed by Jan Kuijpers
- Publisher
- Springer
- Year
- 1974
- Tongue
- English
- Weight
- 716 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0038-0938
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โฆ Synopsis
An interpretation is presented of the decimetric type IV continuum with fine structure on March 6, 1972 and of the corresponding source region, in terms of (~erenkov plasma radiation and alternatively of synchrotron radiation, both in case of coherent and incoherent generation. If the magnetic field strength in the source region is a few gauss, in a stationary situation a loss cone instability develops which generates electron plasma waves coherently. The amount of energetic electrons required for consecutive induced scattering of the plasma waves at the thermal ions into electromagnetic waves is less than in case of synchrotron radiation. It is concluded that the former mechanism provides the explanation of type IV continua with fine structure such as intermediate drift bursts and sudden reductions of the continuum level.
๐ SIMILAR VOLUMES
In the late phase of some complex flare events which produce type IV radio emission, a narrow-band decimetric component with generally a high abundance of spectral fine structures is observed. We identify this late dm continuum as a hypothetical 'switch-off" signature of the equivalent two-ribbon fl