Study of wave-particle interaction from the linear regime to dynamical chaos in a magnetized plasma
Chaos generated by the interaction between charged particles and electrostatic plasma waves has been observed in a linear magnetised plasma. The plasma characteristics, including cross-field ion transport, were investigated by different diagnostic methods based on laser induced fluorescence (LIF) and optical tagging (OT). Electrostatic waves were excited via a 4 ring antenna disposed around the plasma column. The macroscopic wave properties, the kinetic ion dielectric response and the microscopic heating mechanisms were investigated via space- and time-resolved LIF measurements. The existence of a threshold for heating in agreement with the predictions of single particle Hamiltonian theories and the fast time scale for velocity space diffusion were proved in the experiment. Wave induced dynamical chaos in ion orbits appears to be the mechanism responsible for heating. Observations of test particle dynamical evolution indicate an exponential separation of initially close ion trajectories for amplitudes above the heating threshold. Ion orbits in the different wave-particle interaction regimes were obtained using a particular scheme of OT, which provided the two point correlation function in phase space. Perturbed kinetic ion distributions and experimentally reconstructed ion orbits can provide information on the wave fields in the plasma, in the linear and in the non-linear interaction regime, respectively.
Bibliographic Reference: Article: Bulletin of the American Physical Society, Vol. 38 (1993) No. 10, p. 1932
Record Number: 199311629 / Last updated on: 1994-11-28
Original language: en
Available languages: en