Speaker
Description
Nb on Cu structure was proposed instead of the bulk Nd for SRF applications because it is chipper and possesses better thermal properties. For such structure is very important to have good mechanical, electrical, and magnetic properties. An adhesion of Nb on Cu substrate depends on both Nb and Cu crystallinity and Nb deposition technology and thickness of Nb film. The DC entry field Hen and critical temperature were studied in the Nb films deposited by magnetron sputtering on Cu substrate. The Nb/Cu structure was further treated by Nd:YAG laser at four energy doses. The superconducting properties and other characteristics obtained by AFM, SEM, and XRD were compared before and after laser treatment. The laser treatment increased the field of first flux entry by up to 65% compared to a non-irradiated sample. The laser irradiation also led to reduction of surface roughness, improvement of the surface morphology, reduction in crystallites size, and increase of adhesion on 40%. Optical, electrical, and magnetic properties of QPR before and after laser processing were studded.
Acknowledgment
This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871. The authors would also like to thank the ARIES WP15 collaboration team for useful discussions and suggestions.
