JLab, Newport News, Virginia, USA
Université Paris-Saclay, CEA, Gif-sur-Yvette, France
KEK, Ibaraki, Japan
HZB, Berlin, Germany
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
This talk is an overview of the metallographic polishing R&D program covering Niobium and Copper substrates treatment for thin film coating as an alternative fabrication pathway for 1.3 GHz elliptical cavities. The presented research is the result of a collaborative effort between IJCLab, CEA/Irfu, HZB, and KEK in order to develop innovative surface processing and cavity fabrication protocols capable of meeting stringent requirements for SRF surfaces, including the reduction of safety risks and ecological footprint, enhancing reliability, improving the surface roughness, and potentially allowing cost reduction. The research findings will be disclosed.
JLab, Newport News, Virginia, USA
Université Paris-Saclay, CEA, Gif-sur-Yvette, France
KEK, Ibaraki, Japan
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
This article shows a study on an alternative pathway for the fabrication of a complete 1.3 GHz SRF cavity, aiming at improving production reliability, reducing the use of chemical polishing (EP or BCP) which is a costly and safety-critical step, and preserving surface quality after forming. Unlike the conventional pathway, the fabrication process is performed after polishing. This point is crucial as the used polishing technology could be applied only to flat geometries. The performed investigation demonstrates that damages during the fabrication process are considered minor, localized, and limited to the near-surface. Moreover, these studies confirm that the damaged layer (100-200 µm) is mainly caused by the rolling process, and not by the subsequent fabrication steps. A laser confocal microscope and SEM-EBSD technique were used to compare samples before and after forming. The preliminary results are discussed and presented in this paper.
