Material transport by erosion and redeposition on surface probes in the scrape-off layer of JETFunded under: FP2-FUSION 10C
The material transport by erosion and redeposition at the plasma facing wall areas in high temperature plasma experiments has been studied using limiter-like carbon probes with well defined surface deposits and depth markers. The probes have been exposed in the scrape-off layer (SOL) of JET during single discharges. For the evaluation of these experiments, a computer program ERO has been developed. The calculated erosion/deposition rates for carbon as a function of the distance to the last closed flux surface (LCFS) agree well with the experimental results. For a single 4He JET discharge, erosion yields of 530 Angstrom for the Si deposit and 80 Angstrom for V have been measured near the LCFS. A large amount of redeposited Si (about 17% of the sputtered atoms) has been found on the probe surface in co-deposition with carbon on an area not favourable by the proposed model. This observation can be explained by an additional force on the impurity ions (for example the existence of a local electric field) which may cause the deposition.
Bibliographic Reference: Report: JET-P(92)64 EN (1992) 19 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199310244 / Last updated on: 1994-11-29
Original language: en
Available languages: en