Symmetry breaking in ionization wave turbulence

Experimental data of weakly turbulent ionization waves in a plasma glow dis charge (a reaction-diffusion system) are analyzed by biorthogonal decomposi tion. The spatiotemporal dynamics of a single traveling wave and of turbule nce are considered. A biorthogonal decomposition analysis of the symmetry p roperties suggests that turbulence is established here by strong modulation of traveling waves. To mimic this essential feature of the turbulent dynam ics, the plasma discharge is periodically perturbed, and a monochromatic tr aveling ionization wave is modulated in a controlled way. The low-dimension al projection of the spatiotemporal data allows for a reconstruction of the modulation function. Similarities between the periodically perturbed and t he turbulent state support the assumption that ionization wave turbulence c onsists of modulated traveling waves. [S1063-651X(98)06212-6].