Nonlinear longitudinal waves in a two-dimensional screened Coulomb crystal.
Nonlinear interactions of longitudinal waves were observed in a two-dimensional plasma crystal, i.e., a lattice composed of highly charged microspheres immersed in a plasma. The waves were launched by radiation pressure of a laser, and wave spectra in omega-k space were analyzed at various amplitudes of waves. At a sufficiently large amplitude of wave, the second and third wave harmonics satisfying a dispersion relation were observed. As the second harmonic propagates from the excitation region, it was amplified for a small distance, and then damped. The experimental results were compared to a nonlinear wave theory and to a molecular dynamic simulation.
Nunomura
S
S
Max-Planck-Institut für Extraterrestrische Physik, D-85740 Garching, Germany. nunomura@mpe.mpg.de
Zhdanov
S
S
Morfill
G E
GE
Goree
J
J