IMPURITY SOURCES IN JET
In order to study the sources of impurities in JET, collecting sample surfaces have been introduced on probes, and mounted for longer periods on the vacuum vessel walls. These samples and pieces cut from the carbon limiters have been examined by a variety of surface analytical techniques. These results show that during a period of tokamak operation there is significant erosion and deposition of carbon and metallic impurities on the walls and limiters. In particular the limiters progressively become contaminated by metals and this appears to be the main source by which metallic impurities enter the plasma. The metallic contamination can be reduced by the process of carbonization. Models for the migration of impurities by different processes will be discussed.
Bibliographic Reference: 27TH ANNUAL MEETING OF THE DIVISION OF PLASMA PHYSICS, SAN DIEGO (USA), NOV. 4-8, 1985 PAPER 6P50, PROCEEDINGS P.1525
Record Number: 1989124130500 / Last updated on: 1987-01-01
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