Microwave bursts and relative concentration of electrons and protons in solar flare cosmic rays

Consideration is given to the relationship between the parameters of microwave bursts and the relative concentration of energetic electrons and protons (e/p ratio) in solar flare cosmic rays. It is shown that short microwave bursts correspond to solar cosmic ray events with higher e/p ratios. Variations of the e/p ratio are caused by the difference of electron and proton lifetimes in flare loops with different sizes. The dynamics of energetic electrons and protons is discussed in the framework of different pitch-angle diffusion regimes which occur in high and compact coronal loops.