Finest filamentary structures of the corona in the slow and fast solar wind

Recent progress in our understanding of electron density fluctuations observed by radio occultation measurements has demonstrated that a break in the vicinity of 1 Hz in the temporal frequency spectrum of the density fluctuations provides a measure of the size of the finest filamentary structures in the solar corona. Breaks in frequency have been inferred from the density spectra deduced by Coles et al. from 1979-1980 Voyager phase scintillation and spectral broadening measurements. These results show that the finest filamentary structures are found in the extensions or stalks of coronal streamers-the likely sources of the slow solar wind-and are over a factor of 3 smaller than those in the fast wind emanating from coronal holes. The inferred sizes of the finest filamentary structures are approximately 6 km in the slow wind at 8 R. and 22 km in the fast wind at 9.1 R..