The existence of non thermal radio bursts provide evidences for the acceleration of electrons in the solar atmosphere.It is shown, from the characteristics of the bursts, that the electrons are accelerated in at least four different phases:
(1)An impulsive phase which gives μib and III bursts.(2)A gradual phase which gives μIV and S1IV bursts.(3)A quasi-continuous phase which gives S2IV bursts and noise storms.(4)An acceleration by shock waves gives type II bursts.(5)Eventually, another shock-wave acceleration giving the moIV burst.
Acceleration, Containment and Emission of High Energy Flare Particles: Radio Evidence