  Embedded RF contacts are integrated within the ITER ICRH launcher to allow
assembling, sliding and to lower the thermo-mechanical stress. They have to
withstand a peak RF current up to 2.5 kA at 55 MHz in steady-state conditions,
in the vacuum environment of themachine.The contacts have to sustain a
temperature up to 250{\textdegree}Cduring several days in baking operations and
have to be reliable during the whole life of the launcher without degradation.
The RF contacts are critical components for the launcher performance and
intensive R&D is therefore required, since no RF contactshave so far been
qualified at these specifications. In order to test and validate the
anticipated RF contacts in operational conditions, CEA has prepared a test
platform consisting of a steady-state vacuum pumped RF resonator. In
collaboration with ITER Organization and the CYCLE consortium (CYclotronCLuster
for Europe), an R&D program has been conducted to develop RF contacts that meet
the ITER ICRH launcher specifications. A design proposed by CYCLE consortium,
using brazed lamellas supported by a spring to improve thermal exchange
efficiency while guaranteeing high contact force, was tested successfully in
the T-resonator up to 1.7 kA during 1200 s, but failed for larger current
values due to a degradation of the contacts. Details concerning the
manufacturing of the brazed contacts on its titanium holder, the RF tests
results performed on the resonator and the non-destructive tests analysis of
the contacts are given in this paper.
