ANALYSIS OF EROSION AND TRANSPORT OF CARBON IMPURITY IN THE TFTR INNER BUMPER LIMITER REGION

[摘要] Carbon sputtering and transport on the TFTR inner graphite bumper limiter is investigated with the impurity transport code REDEP. Analysis is carried out for a series of ohmic discharges in TFTR. Predictions for Z(eff) in the core plasma agree well with in situ experimental measurements. Runaway self-sputtering of carbon is predicted at low densities and high edge plasma temperatures when the limiter surface was purged of deuterium. Surface erosion and deposition is analyzed. In general, redeposition reduces the peak erosion by about a factor of 5. Analysis is also carried out for a typical neutral beam heated discharge with a noncircular plasma. Spatial surface erosion and deposition profiles are compared qualitatively with beta backscattering measurements of metal deposition found on the limiter.

[发布日期] 1992-12-01

[效力级别]  Proceedings Paper