Interference Origin of the Fine Structure in the Dynamic Spectra of Solar Radio Bursts

摘要

The multibeam propagation of radio waves in the solar plasma is analyzed, because the emission from a solar flare passes through an inhomogeneous solar atmosphere on its way to the observer. A formula (a mathematical model) for calculating the structure of the dynamic spectrum for flare radio bursts has been obtained. Comparison of the calculated spectra with the observed ones shows that the results of interference explain the formation of a zebra structure and the separation of its stripes into individual spikes, describe the time profile of the spikes, and explain the properties of fibers, ropes of fibers, and chains of "point" bursts. The similarity of the dynamic spectra testifies that the fine structure of the spectra is formed not in the emission source but as a result of the propagation of waves through the solar corona and interplanetary space.