Development of a thermo-hydraulic bypass leakage test method for the Wendelstein 7-X target element cooling structure

A facility for testing the cooling structure to ensure the quality of the target element heat sink is under construction at IPP Garching. This test bed has been built up to do a proof of concept study with a hydraulic mock up, built from the same material as the target elements, but can be opened for artificial gap manufacture. ss in the cooling structure was the main reason for the overheating of CFC tiles, which resulted in a defect by cracking of the CFC–AMC-Cu interlayer in pre-series 3. The cooling structure is built from two half-shells, in both a half pipe is milled [1]. To correlate the thermal response function to the artificial bypass gaps the time constant of the cool down was used. The results of the measurements are presented and compared with the calculated results.