Properties of high-β microturbulence and the non-zonal transition

M. J. Pueschel, D. R. Hatch, T. Görler, W. M. Nevins, F. Jenko, P. W. Terry, D. Told
2013 Physics of Plasmas  
The physics underlying the Non-Zonal Transition [M.J. Pueschel et al., Phys. Rev. Lett. 110, 155005 (2013)] are explored in detail, and various studies are presented which support the theory that critically weakened zonal flows are indeed responsible for the failure of ion-temperaturegradient-driven turbulence at high plasma β to saturate at typical transport values. Regarding flux-surface-breaking magnetic fluctuations and their impact on zonal flows, numerical approaches to obtaining zonal
more » ... obtaining zonal flow residuals are elaborated on, and simulation results are shown to agree with analytical predictions, corroborating the interpretation that flux-surface-breaking magnetic fluctuations cause the transition. Consistently, the zonal-flows-related energetics of the turbulence are found to change fundamentally when exceeding the threshold.
doi:10.1063/1.4823717 fatcat:6snqqq4dzvhtbkogzc2d76cmvq