PROPAGATION OF TYPE III SOLAR BURSTS RADIO EMISSION THROUGH THE CORONA. 2. FREQUENCY DRIFT RATE

摘要

The paper suggests an analysis of the effects of propagation of the electromagnetic waves, generated in the solar coronal plasma of variable density by fast electron beams, upon the frequency drift rate of type III radio bursts. Analytic expressions for the drift rate have been derived for small-sized beams in two models of the corona. In the case of a finite-sized particle beam, the rate of the frequency drift is estimated numerically for a set of observed velocity vectors of the electron beam. As it occurs, decameter wavelength type and "fast" type III bursts can be given an interpretation within a single model. The frequency dependence of the drift rate is analyzed numerically for a particle beam of expanding size. Analytical approximation of this dependence is in good agreement with the empiric formula suggested in 1973 by Alvarez and Haddock, based on observational data.