Difference: FJPPLAccelerateurRD (21 vs. 22)

Firstly, it consists in applying directly on Niobium sheets an optimized metallographic polishing procedure aiming at removing the damaged layer generated during Niobium sheet manufacturing. This process has been studied in the framework of H2020 European program, European Nuclear Science and Applications Research - 2 (ENSAR2) project (grant agreement N°654002) in collaboration with CEA/IRFU.

Secondly, polished Niobium sheets have to be formed and welded to build an elliptical cavity. However, conventional forming techniques might not be applicable as this process would damage too significantly the pre-polished surfaces. All the benefits of the high-quality metallographic polishing would then be lost as a conventional chemical treatment would need to be performed.

The aim of this collaborative proposal is to address this second step of the alternative pathway for cavity fabrication. KEK has the experience, ability and facilities to build elliptical cavities. IJCLab/IRFU have the ability and equipment to perform the optimized metallographic polishing procedure for SRF applications and proceed with surface characterization. Sharing and combining our experience and effort will allow us to address, in a very efficient manner, the second step of this alternative pathway.