The Tore Supra toroidal pump limiter: experience feedback of HHF elements series manufacture

Since 1992, reliable high heat flux PFCs based on copper alloy heat sink structures and a CFC armour, have been developed. The final result is an actively cooled high heat flux element that is capable of removing up to 10 MW·m^-2 stationary operating conditions. About 600 of these high performance individual components have then been manufactured and assembled in order to equip a toroidal pump limiter (TPL). This major in-vessel component consists of a flat toroidally continuous disk (R_i=2.2 m, R_o=2.7 m) covering a 7.6 m² area and made of 574 radial high heat flux elements called "fingers". Following a promising previous manufacture of 200 "short fingers elements" dedicated to RF antenna limiters, the fabrication of actively cooled long fingers elements required to equip the TPL was launched in 1997 in the framework of CIEL project. Although some issues appeared during series fabrication, requiring repair processes development, the final deliveries have been achieved successfully end 2001. The paper deals with the experience feedback that was gained all along the four years duration of the TPL components manufacture. We will show where issues were encountered, how solutions were found to achieve the fabrication of components and will highlight what are the main technical lessons to be learned: acceptance criteria, choice of materials, margins of processes. Finally a proposal of an alternative optimised design is presented, fruit of the experience gained and progress performed from this up to now, unique series manufacture of actively cooled plasma facing HHF components. Such feedback experience is considered highly relevant and available to ITER as well as to Wendelstein 7-X.