Abstract. Abstract: The paper presents measurements of radial variations of the floating potential at the Tore Supra (TS) tokamak ergodic divertor plate and in front of the CASTOR tokamak lower hybrid (LH) grill, due to the presence in these two locations of the fast particle beam generated in front of LH grills. The paper also presents a scanning electron microscope (SEM) and secondary ion mass spectrometric (SIMS) analysis of an eroded graphite tile from the TS LH grill guard limiter, performed in order to check the authors' theoretical conclusion that fast ions can be generated in a thin layer in front of LH grills and that they can contribute to damage of tokamak vessel components. The paper first presents theoretical conclusions that are relevant to the experimental data and then the experimental results.
IAEA 2001