STUDY OF WAVE PARTICLE INTERACTION FROM THE LINEAR REGIME TO DYNAMICAL CHAOS IN A MAGNETIZED PLASMA

The onset of chaotic ion dynamics in electrostatic waves is investigat ed in a linear magnetized plasma. The existence of a threshold for hea ting in agreement with the predictions of single particle Hamiltonian theories and the fast time scale for velocity space diffusion are obse rved in the experiment. Measurements of test-particle dynamics indicat e an exponential separation of initially close ion trajectories for am plitudes above the heating threshold. Ion orbits in the different wave -particle interaction regimes are inferred using an optical tagging di agnostic method, which provides the two point correlation function in phase space.