PERIODIC NONLINEAR WAVE-WAVE INTERACTION IN A PLASMA DISCHARGE WITH NO EXTERNAL OSCILLATORY DRIVING-FORCE

Experimental measurements of time series and frequency spectra charact erize a periodic nonlinear interaction between pairs of self-excited, propagating, ionization waves simultaneously present in the positive c olumn of a neon glow discharge. No periodically varying external drivi ng force is applied. The interaction is the spatio-temporal extension of the previously established temporal periodic pulling process, the i ncomplete entrainment of a driven nonlinear oscillator. The particular mode playing the role of the driving perturbation in the interaction can be selected and is identified by inspection of the asymmetric, mul tisideband spectrum of Light fluctuations, which reflect the system's dynamics. A comparison between the spatio-temporal and temporal period ic pulling shows that the former is associated with a relatively stron g driving force. (C) 1996 American Institute of Physics.