Electron Beams in the Low

Selected high resolution spectrograms of solar fast-drift bursts in the 6.2{8.4 GHz range are presented. The bursts have similar characteristics as metric and decimetric type III bursts: rise and decay in a few thermal collision times, total bandwidth > 3% of the center frequency, low polarization , drift rate of the order of the center frequency per second, and are association. They appear in several groups per are, each group consisting of some tens of single bursts. Fragmentation is also apparent in frequency; there are many narrowband bursts randomly scattered in the spectrum. The maximum frequency of the bursts is highly variable. The radiation is interpreted in terms of plasma emission of electron beams at plasma densities of more than 10 11 cm ?3. At this extremely high frequency, emission from the plasma level even at the harmonic is only possible in a very anisotropic plasma. The scale lengths perpendicular and parallel to the magnetic eld can be estimated. A model of the source region and its environment is presented.