SURFACE ANALYSIS OF THE CENTRAL AND TOP PART OF A 1984 JET GRAPHITE LIMITER AND OF 1984 JET LONG TERM SAMPLES
The JET graphite limiter (top and central part) from octant IV as well as long term samples (LTS) and a bellow protection plate all exposed to plasma discharges during the 1984 experimental period have been investigated by means of surface layer analyses techniques. The limiter tiles show characteristic differences in the deposition of metals compared to the 1983 limiter reflecting the higher power loads from the plasma achieved in 1984. Analysis of the LTS reveals a close correlation between erosion sources at the vessel walls of JET and the redeposition areas. This indicates that a major part of the metals eroded at the limiter surface or the wall during normal discharges may not enter the central plasma, but is immediately redeposited close to the area of erosion. Deuterium was found on the sides of the graphite limiter, with concentrations exceeding the amount which could be deposited by simple implantation by at least an order of magnitude. This indicates a code position of carbon and deuterium at those areas.
Bibliographic Reference: WRITE TO MAX-PLANCK-INSTITUT FUER PLASMAPHYSIK, 8046 GARCHING BEI MUENCHEN (GERMANY), MENTIONING REPORT IPP-JET NO 29, 1985
Record Number: 1989124050000 / Last updated on: 1987-01-01
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