Edge turbulence controlled by topologically self-optimized fluxes in fusion devices

Abstract

The integration of a theory regarding the dynamics of averaged magnetic moment in a turbulent setting with the concept of a self-optimized cascade loop of helical fluxes, either spontaneously or intentionally generated near the separatrix, enables the derivation of spectral laws for the floating potential and ion saturation current, which align with findings from various experiments conducted on tokamaks, stellarators, and RFX-mod reversed field pinches. The notion of distributed chaos enables a quantitative evaluation of the randomness levels of chaotic/turbulent states observed inside and outside the separatrix, linking them to self-optimized helical fluxes.