Electron cyclotron masers during solar flares
Abstract
It has been suggested that solar microwave spike bursts are due to electron cyclotron maser action. The objective of the study reported here is to explore a simple model for the dynamics of the electrons producing the maser emission and to use the model to investigate the conditions under which the maser turns on. It is shown that there are two phases in which maser action is likely to occur following a solar flare. In the later phase, loss cones in upgoing particles develop and are unstable to wave growth; the resulting maser produces radiation at low harmonics. Maser action is also likely to occur in an earlier phase when the particles are predominantly downgoing. The resulting maser emits radiation which should be reflected or reabsorbed at a level where its frequency equals the critical frequency of the appropriate mode. The radiation propagates nearly perpendicular to the field lines so that heating over a large area is possible. The implications of the results obtained are briefly examined.
- Publication:
-
Publications of the Astronomical Society of Australia
- Pub Date:
- 1983
- DOI:
- 10.1017/S1323358000016829
- Bibcode:
- 1983PASA....5..188W
- Keywords:
-
- Electron Cyclotron Heating;
- Masers;
- Radio Frequency Heating;
- Solar Flares;
- Solar Radio Bursts;
- Cyclotron Resonance;
- Energetic Particles;
- Harmonics;
- Plasma Interactions;
- Solar Physics