On the theory of type III radio bursts in the nonhomogeneous interplanetary space (quasi-linear approximation)

Within the limits of geometrical optics frequency characteristics of perturbations of one-dimensionally non-uniform system “electron beam–solar wind plasma” are investigated in linear approximation on the basis of Maxwell equations closed by the derived constitutive equation. The beam is generated by the active region during solar flares and it appears as a source of type III radio emission in the interplanetary space. The appropriate dispersion equation is solved. Resonance interaction of wave with electron beam appears to happen only in two space points. Such transient (pointwise) mechanism of resonance throws light on one of the basic problems of physics of electron beams generated by solar flares: incomparably more long-term time of their existence compared to the time of existence resulting from the former theoretical estimates of velocity of beam energy loss on radiation within the limits of homogeneous medium. The degree and time of electron beam dissipation were determined in quasi-linear approximation.