Millisecond solar radio spikes

G.D.Fleishman

Abstract

Currently available models of one of the most intriguing types of nonstationary solar radio emission, millisecond solar radio spikes, are discussed. A comparative analysis of the model implications and the existing observational data (concerning temporal, spectral, spatial, polarization, and other properties) yields the outline of what appears to be the most realistic radio spike model. This outline is as follows.The spikes are produced by the electron cyclotron maser mechanism. The cyclotron loss-cone instability is caused by fast electrons distributed over energies according to a (broken) power law. The angular part of the distribution function (whose exact form is, as yet, undetermined) suffers fluctuations due to the magnetic field inhomogeneities that arise in the flare loop as a consequence of the primary energy release. In some regions of the loop the distribution is anisotropic enough to produce the electron cyclotron instability; it is that `micro-traps' where individual spikes form. Key problems and areas of future theoretical and experimental research are suggested and discussed.
 
 

Authors: G.D.Fleishman & V.F.Melnikov