NEUTRON BRAGG EDGE IMAGING (NBEI) MEASUREMENT OF AXIAL STRAINS IN A W/Cu/CuCrZr MONO-BLOCK DEVELOPED FOR PLASMA-FACING COMPONENTS IN FUSION REACTOR TECHNOLOGY

It is proposed to utilize Neutron Bragg Edge Imaging (NBEI) to measure the axial strains in a W/Cu/CuCrZr mono-block sample fabricated as a prototype of the divertor, a crucial plasma-facing component in fusion reactor technology. This sample is constituted by a CuCrZr cooling pipe 1.5 mm thick, brazed by a thin, Cu alloy layer to a protective pure W tile. Complex strain distributions are expected around the joining region and inside the CuCrZr pipe; therefore NBEI is the appropriate technique to carry out such investigation with the spatial resolution needed to allow for a meaningful comparison with numerical strain predictions. Un-strained references both for W and for CuCrZr will be measured as well to correct the data measured on the brazed mono-block sample. The obtained axial strain distribution through the sample will provide essential information needed to qualify the adopted fabrication method and its suitability for the construction of large scale divertor components.