Collective wave-particle interactions in solar type IV radio sources
Abstract
This thesis proposes a coherent emission mechanism for type IV decimetric radio bursts, a unified explanation of solar type IV decimetric continuum storms and zebra patterns, and a possible emission mechanism for intermediate drift bursts. Observations of solar type IV bursts, continuum storms, and fine structures are reviewed. The fine structures and source regions are described, and velocity-space instabilities are analyzed. It is suggested that type IV bursts are produced by the induced conversion of coherently generated Cerenkov plasma waves into electromagnetic waves. It is proposed that continuum storms and zebra patterns originate in plasma waves excited at the upper hybrid frequency by a loss-cone distribution of fast electrons superposed on the ion background, that the patterns result when the inverse fractional density of the fast electrons exceeds the ratio of the electron plasma and cyclotron frequencies, and that the storms occur in the opposite situation. It is shown that the coupling of whistler solitons and Langmuir waves can produce intermediate drift bursts when the phase velocity of the Langmuir waves is of the order of the speed of light.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1975
- Bibcode:
- 1975PhDT.........1K
- Keywords:
-
- Coherent Radiation;
- Particle Interactions;
- Solar Storms;
- Type 4 Bursts;
- Wave Interaction;
- Cerenkov Radiation;
- Electromagnetic Wave Transmission;
- Electron Plasma;
- Fine Structure;
- Plasma Waves;
- Solar Activity Effects;
- Whistlers;
- Astrophysics