Synchronization mechanism and Arnold tongues for dust density waves.
The nonlinear phenomenon of synchronization is characterized experimentally for dust density waves, i.e., dust acoustic waves, which are self-excited due to an ion streaming instability. The waves propagate in a dust cloud with a natural frequency of 22 Hz. We synchronize these waves to a different frequency using a driving electrode that sinusoidally modulates the ion density. We study four synchronized states, with frequencies that are multiples of 1, 2, 3, and 1/2 of the driving frequency. Comparing to phenomena that are typical of the van der Pol paradigm, we find that synchronization of our waves exhibit the signature of the suppression mechanism but not that of the phaselocking mechanism. Additionally, synchronization of our waves exhibits three characteristics that differ from the van der Pol paradigm: a threshold amplitude that can be seen in the Arnold tongue diagram, a branching of the 1:1 harmonic tongue at its lower extremity, and a nonharmonic state. The latter state appears to be a nonlinear oscillation; it is neither at the natural frequency nor a synchronized state.
Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA. suranga-ruhunusiri@uiowa.edu
W D Suranga
WD
Ruhunusiri
J
J
Goree
D000465:Algorithms; D016477:Artifacts; D001703:Biophysics / Q000379:methods*; D004391:Dust; D004867:Equipment Design; D005583:Fourier Analysis; D007091:Image Processing, Computer-Assisted; D015233:Models, Statistical; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D009991:Oscillometry / Q000379:methods*; D010316:Particle Size; D013997:Time Factors
D004391:Dust