Mechanical model for the plasma maser effect

A Fermi-like pinball model is proposed for the nonlinear plasma maser effect, or turbulent bremsstrahlung, in the nonlinear interaction of plasma particles and waves. The model consists of a system of many noninteracting particles bouncing elastically between two oscillating walls. The walls act as energy and momentum sources and sinks for the particles, analogous to the wave fields in a weakly turbulent plasma. The oscillation amplitudes and frequencies of the walls determine the dynamics and distribution of the particles. The resulting asymptotic velocity distributions agree qualitatively with existing weak turbulence theories. It is also found that the second wall, which simulates the effect of the nonresonant wave-particle interaction, can destroy correlations in the particle dynamics and lead to the formation of a high-energy tail in the velocity distribution.