OVERVIEW OF THE JAPANESE MOCK-UP TESTS FOR ITER HIGH HEAT-FLUX COMPONENTS

This paper reviews the present status of development of ITER high heat flux components in the ITER Japanese Home Team. Special emphasis is l aid on high heat flux tests of divertor mock-ups developed in JAERI. J AERI fabricated a divertor mock-up with parallel cooling tubes, and te sted it in high heat flux test facilities. The mock-up successfully en dured a heat load of 5 MW m(-2), 15 s for 10000 cycles, and a heat loa d of 20 MW m(-2), 15 s for 1000 cycles, which are equivalent to the st eady-state heat load and the transient heat load of the ITER requireme nts, respectively. Based on this encouraging result, large mock-ups we re fabricated, which have almost the full-length of the ITER divertor plate. For the upper section of the target, where heat fluxes are lowe r, CVD tungsten is proposed as the armor. Small divertor mock-ups have been fabricated with a 2-mm thick CVD tungsten layer on a copper heat sink to evaluate these fabrication processes. In parallel with those activities, improvement of bonding techniques and armor materials has been carried out, such as brazing with a non-silver braze and developm ent of 3D CFCs. (C) 1998 Published by Elsevier Science S.A. All rights reserved.