On the free divergence of a fast electron flux in the solar corona under nonstationary injection

Considered is evolution of a fast electron flux injected in the corona from the solar flare region and exciting Langmuir waves (plasmons) which are transformed to the 3d type radio bursts. The ''retardation'' of plasmons with respect to the non-stationary flux in a non-homogeneous coronal plasma allows to treat the motion of the stationary part of the flux as free outflow. It is supposed that in the flare region quasiequilibrium plasma heating takes place. Different models of non-stationary injection are discussed in the cases of quasi-equilibrium (exponential) and non-equilibrium (power) energy spectrum of electrons in the source. It is shown that the free outflow of the electron flux at non-stationary injection results in the formation of a distribution function with sharp maximum, its position depending weakly on the choice of the injection model. The calculation results are compared with the experimental ones. The evolution diagrams of the energy spectrum of electrons obtained in processing the data of observations at ''IMP-6'' sputnik, are analyzed. It is found that the qualitative picture of injection mechanism may be described as non-stationary plasma acceleration (heating) at the current layer break, accompanied by turbulent electron heating at the tail of quasi-equilibrium distribution