Introduction to proceeding of second international conference on surface effects in controlled fusion devices

Abstract

Deposition probes are commonly used to determine plasma edge characteristics in tokamaks. Such probes are frequently analyzed using accelerator-based techniques and can yield information on impurity fluxes, hydrogen fluxes and energies and surface erosion rates in the plasma edge. Several types of deposition probes have been employed to investigate the plasma edge region of the TEXTOR tokamak in Jülich, FRG. TEXTOR is a moderate size tokamak (major radius = 1.75 m) that is capable of 2–3 s discharges and contains a liner that can be heated to 600°C. These capabilities make TEXTOR particularly attractive for the study of plasma-wall interactions. Several countries, including the United States, Sweden and the host nation, are carrying on active research programs in the area of plasma edge studies. This research has included measurements of plasma, impurity and power fluxes at various radii in the scrapeoff layer. The results achieved in characterizing the plasma edge in these recent probe studies on TEXTOR will be reviewed.