Characterization of transport in the stochastic edge layer of TEXTOR by analysis of the radial and poloidal distribution of electron density and temperature

Abstract

At TEXTOR the dynamic ergodic divertor (DED) induces a stochastic edge layer by a resonant magnetic perturbation to control heat and particle exhaust. In this paper the characterization of its generic transport properties is described. The radial and poloidal distribution of electron density and temperature is analyzed accompanied by observations of the particle flux to the DED target. These experimental results are compared to the calculated magnetic topology and to results from EMC3/EIRENE modeling. Thereby, the existence of two poloidally separated transport domains is demonstrated: laminar flux tubes are dominated by parallel transport to the DED target – they act analogous to a classical scrape-off layer. In contrast, the adjacent ergodic domains show stochastic transport characteristics with enhanced radial transport.