Edge turbulence in tokamaks, stellarators and reversed field pinches

Abstract

Characteristics of electrostatic and magnetic turbulence in the edge of tokamaks, stellarators and reversed field pinches are compared and contrasted. Scalings of turbulent fluctuation levels and wave numbers are discussed. Electrostatic turbulence is shown to explain edge density scale lengths in all three device types. Electrostatic fluctuations also determine edge thermal transport in tokamaks and stellarators, while magnetic fluctuations explain edge thermal transport in reversed field pinches and runaway electron transport in tokamaks and stellarators.