Overview of tracer techniques in studies of material erosion, re-deposition and fuel inventory in Tokamaks

C-13 labeled methane and rhenium-boron coated plates were used at the JET tokamak as tracers for studies of the material transport, its erosion and re-deposition. Experimental procedures are described. The results are discussed in terms of processes underlying the material transport and the change of morphology of targets exposed to the plasma: physical sputtering, chemical erosion, prompt re-deposition. The influence of wall materials on fuel inventory is also addressed. C-14 measurements in the TEXTOR tokamak are presented and possibilities of using C-14 in carbon migration studies are considered. (C) 2004 Elsevier B.V. All rights reserved