Zonal profile corrugations and staircase formation: Role of the transport crossphase

Abstract

Recently, quasi-stationary structures called $E\times B$ staircases were observed in gyrokinetic simulations, in all transport channels [Dif-Pradalier et al. Phys. Rev. Lett. 114, 085004 (2015)]. We present a novel analytical theory - supported by collisional drift-wave fluid simulations - for the generation of density profile corrugations (staircase), independent of the action of zonal flows: Turbulent fluctuations self-organize to generate quasi-stationary radial modulations $\Delta \theta (r,t)$ of the transport crossphase $\theta$ between density and electric potential fluctuations. The radial modulations of the associated particle flux drive zonal corrugations of the density profile, via a modulational instability. In turn, zonal density corrugations regulate the turbulence via nonlinear damping of the fluctuations.

6 pages, 5 figures (low-quality figures)

References in corpus (3)

• Bifurcation in electrostatic resistive drift wave turbulence
• Formation of solitary zonal structures via the modulational instability of drift waves
• Effects of zonal flows on transport crossphase in dissipative trapped-electron mode turbulence in edge plasmas

Cited by in corpus (3)

• Mesoscopic transport in KSTAR plasmas: avalanches and the $E\times B$ staircase
• Limit Cycle Oscillations, response time and the time-dependent solution to the Lotka-Volterra Predator-Prey model
• Friction-induced scale-selection in the extended Cahn-Hilliard model for zonal staircase