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MICROWAVE
TESTING OF A CVD DIAMOND TORUS WINDOW PROTOTYPE FOR ITER * T. A. Scherer, R. Heidinger, A. Meier Institut für Materialforschung IMF-I ,Association EURATOM-FZK,
Forschungszentrum Karlsruhe, D-76021 Karlsruhe, Germany K. Takahashi
, K. Kajiwara, K. Sakamoto, Plasma Heating Technology
Group,
For the plasma
engineering of ITER, EC launchers will be used at the mid and top port levels.
The EU is preparing the procurement of the upper port plug and JA the
procurement of the equatorial. Part of these studies is to verify the window
design and to work out, whether a concept is available for both launchers. To
this goal, first experiments with low and high power mm-waves are performed
and will be presented. The high
power RF behavior of torus window assemblies with corrugated waveguides is
being investigated by using IR imaging technique during high power microwave
loading up to 1 MW at a frequency of 170 GHz at the JAEA gyrotron facility. Short
and long pulse experiments are being performed to determine the temperature
distribution over the whole diamond window area and the efficiency of the
indirect cooling by a copper cuff. The occurrence of arcing is being studied
as part of evaluation of the assembly design. For a
characterization of the dielectric losses a low power measurement in a
Fabry-Perot resonator setup at 170 GHz of the bare as-grown diamond disk will
be compared with the brazed disk in the window housing. The evaluation of the
curvature of the diamond disk is used as indicator of the residual stresses
introduced in the joining process. ________________________________ * Part of
this work supported by the European Communities, was carried
out within the framework of the European Fusion Development Agreement. |