A model explaining type IV continuum bursts by coherent nonlinear interaction of Bernstein waves

The investigated model supposes Bernstein waves emerging from Harris instabilities at a definite coronal level. The nonlinear process is considered for a higher region, where the quasimonochromatic waves forming the primary spectrum are reflected. Spatial dispersion takes place corresponding to the decreasing magnetic field. Thus each quasimonochromatic wave can be treated separately. According to the nonlinear resonance condition there result electromagnetic waves of twice the primary frequency, the power density of which is calculated. Assuming a coherence time of 480 periods and an oscillation velocity of the electrons of 10^-3 times the thermal velocity the effective radiation temperature 10¹¹ K of a type IVmA-burst is obtained at about 180 MHz, if the range of the nonlinear interaction is about 3.9 km long. In the discussion the interpretation of occurring zebra patterns is treated.