Search for chaos in the transition to drift wave turbulence

In the transition to fully developed turbulence one may encounter chaotic regimes, as has been demonstrated both theoretically and experimentally in a variety of flows, including within magnetized plasmas. Such regimes appear as windows of low-dimensional order, allowing for a better understanding of the underlying nonlinear dynamics, which may in turn allow for new avenues of control. We have recently begun a study of the turbulent transition in the Controlled Shear De-Correlation Experiment (CSDX), a helicon-powered magnetized plasma column at UCSD, in light of chaotic signatures such as the maximum Lyapunov exponent as derived from Langmuir probe time-series. We report our preliminary results on the role of chaos in the transition in general and with respect to the emergence of a self-organized shear layer (zonal flow) in particular.