High heat flux testing of EU tungsten monoblock mock-ups for the ITER divertor

The test results fulfilled the ITER qualification requirements, although a few items did not sustain the extended test program (additional 700 cycles at 20 MW/m2), the analysis of the results gave indications on potential improvements, in particular concerning the W material itself with the objective to remove the self-castellation of the W monoblocks and concerning the thermo-mechanical fatigue performances of the CuCrZr heat sink. In addition, some critical heat flux experiments, whose results confirmed those previously obtained were also performed.