Nonlinear relaxation of an electron beam and reacceleration of fast electrons in solar flares

A numerical solution is found for the relaxation of an electron beam in sol ar-flare plasma, taking into account the nonlinear scattering of Langmuir w aves on thermal ions of the plasma for beams with a mean velocity (10-20)v( Te). This process leaves the relaxation time virtually unchanged compared t o the quasi-linear case, but leads to additional electron acceleration simi lar to by a factor of 1.5 and a decrease in the total loss of the electron beam. The predicted X-ray emission from such reaccelerated electron beams i s in full agreement with observed values during solar flares.