CLEANING OF METAL-CONTAMINATED GRAPHITE TILES OF THE TEXTOR ALT-II PUMP LIMITER BLADES
Graphite is the preferred material for plasma facing components in today's fusion experiments and it is a prime candidate material for coming fusion devices. It is possible for the graphite surface to become contaminated, e.g. with metals, which leads to undesired effects on the plasma. Instead of an expensive exchange for new graphite parts, an appropriate cleaning method should be applied. This paper describes comparative tests of different mechanical cleaning methods applied to metal contaminated graphite tiles of the ALT-II toroidal belt pump limiter in the TEXTOR tokamak. Scanning electron microscope techniques are used to characterise the cleaning efficiency. Best results are obtained by sandblasting the graphite surface with boron carbide grains, which proves to be a very effective, inexpensive and fast cleaning method. After reassembly of the tiles, in-situ tests by exposure to tokamak discharges show undetectably low (below 1.0E-5) metal concentrations in the TEXTOR plasma.
Bibliographic Reference: ARTICLE: JOURNAL OF NUCLEAR MATERIALS, VOL. 168 (1989) NO. 1&2, PP. 58-64
Record Number: 1989128078100 / Last updated on: 1990-11-09
Available languages: en