Relaxation oscillations in the source of S-bursts of Jovian decametric radio emission

A mechanism is proposed by which long-period (tens of milliseconds) trains of S-bursts of Jovian decametric radio emission are produced. Those trains of S-bursts are caused by pulsed diffusion in momentum space of fast electrons. The diffusion is due to plasma waves generated by fast electrons under the cyclotron reasonance conditions. Conditions for appearance of a periodic regime are specified. Dependence of the period on the electron flux in the source is found. It is shown that a periodic regime with periods consistent with the observations is possible in the Jovian ionosphere environment.