A modified fermi model for wave-particle interactions in plasmas.
Wave-particle interactions in plasmas are investigated through a nonlinear map that describes elastic collisions between an ensemble of particles and two barriers. The amplitude of the barriers, proportional to the energy of the wave, can increase or decrease due to the sequence of stochastic collisions. After an initial exponential decrease, the nonlinear strong trapping regime is characterized by low-frequency oscillations of the amplitude of the barriers around a certain saturation value. This is a transitory phenomenon stemming from the dynamical approach towards equilibrium in the wave-particle conservative system.
De Marco
Rossana
R
Dipartimento di Fisica and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Università della Calabria, Ponte P. Bucci Cubo 31C, 87036 Rende (CS), Italy.
Carbone
Vincenzo
V
Veltri
Pierluigi
P