On relaxation of the electron distribution function in resonant striation-like fields

Relaxation of an approximately $\delta$-shaped distribution function of electrons injected into $P$ and $R$ striation-like fields on one of the resonant trajectories is analyzed. It is shown that as a result of energy diffusion, electrons appear on other resonant trajectories after several periods. Ultimately, a steady state corresponding to the distribution function in the $P$ and $R$ strata is formed as a result of compression to resonant trajectories and energy diffusion.