Material damage in graphite by run-away electrons
Graphite limiters in the KFA tokamak TEXTOR are hit by run-away electrons, which "burn" craters into the material surface. The craters are formed by material erosion and/or sublimation, by chipping off thin laminates from the surface and also by redeposition of graphitic material. Thin metallic layers are detected which may be redeposited independently from the run-away electron event, and which can be found outside the run-away electron crater. The redeposited carbon shows primarily two types of structure, namely orientated pyrocarbon and carbon-black like material. The crater is investigated by metallography, optical microscopy, secondary electron microscopy combined with energy-dispersive X-ray analysis, and automatic quantitative image analysis. The examined parameters are crater geometry, cracking behaviour and type and structure of redeposited material.
Bibliographic Reference: Article: Journal of Nuclear Materials, Vol. 162-164 (1989) pp. 970-975, North-Holland, Amsterdam (NL)
Record Number: 199010664 / Last updated on: 1994-12-01
Original language: en
Available languages: en