Speaker
Description
In recent years, the use of alternatives to bulk Nb in the fabrication of SRF cavities, including novel materials and fabrication techniques, have been extensively explored by the SRF community. One of these new methodologies is the use of a superconductor-insulator-superconductor (SIS) multilayer film coating. Typically, these have been envisaged for use with bulk Nb cavities. However, it is possible to combine the benefits of SIS coatings with the benefits of coated Cu cavities. It is also clear that the use of so-called energetic deposition techniques, such as HiPIMS, provide significant benefits over typical DC MS coatings, in terms of SRF performance.
In light of this, experiments have been completed in the pursuit of HiPIMS-deposited, multilayer SIS film coatings on copper samples. The SIS system studied here was Nb-AlN-NbN. This research culminated in the deposition of two QPR samples, using the final optimized coating process. This contribution details the development of these coatings and the required optimization of the coating parameters of the separate material systems, through the use of multiple material and superconducting characterization techniques.
