Manufacturing and high heat-flux testing of brazed actively cooled mock-ups with Ti-doped graphite and CFC as plasma-facing materials

In the frame of the EU project ExtreMat new Ti-doped isotropic graphites and carbon fibre-reinforced carbons (CFCs) with high thermal conductivity and reduced chemical erosion were brazed to a CuCrZr heat-sink to produce flat-tile actively cooled mock-ups (MUs). Brazing was done using a low CTE interlayer to shift the stresses to the metal?metal interface. These MUs were exposed to high heat-fluxes in the electron beam facility JUDITH. Screening tests were conducted increasing the heat load stepwise up to 15?MW?m?2, followed by 100 cycles at 15?MW?m?2, subsequent screening up to 20?MW?m?2 and 100 cycles at 20?MW?m?2. All MUs withstood screening at 15?MW?m?2 and most of them survived screening at 20?MW?m?2. Ti-doped CFC MUs showed a significant improvement compared with the undoped reference CFC, surviving several cycles at 20?MW?m?2 on all tiles. One of the Ti-doped graphite MUs withstood 100 cycles at 20?MW?m?2 on one tile, representing a promising result.