Some features of fiber formation in type 4 radiobursts

Fiber bursts with intermediate drift of the frequency are one of the types of a fine structure of solar continuous radiobursts of the 4-th type in decimeter and meter ranges of waves or at frequencies from ∼1000 to ∼100 MHz. At the dynamic spectrum they are narrow (∼1MHz per 150 MHz) bands in radiation and absorption drifting mainly to low frequencies. Main properties of fiber radiation are satisfactority explained by interaction of the Langmuir waves (l) responsible for continuous radiation of the 4-th type with whistlers(w) excited in sources of the 4-th type by fast particles with cone distribution in rates. Observations of fibres with unusual parameters are presented and analyzed in his paper. In particular, fibers with the unusual position of the absorption band are observed from the high-frequency edge relatively to the fiber in radiation and fibers in radiation bordening the absorption band from both sides. In this connection the possibility of l- and w-waves coalescence (l+w→t) and their decays at differential frequency ωt-=ωl-ωw is shown. In this case directivity of three waves plays the important role