JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - UNPB AU - Spina, T. AU - Grassellino, A. AU - Romanenko, A.S. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Lesage, Ana ED - Schaa, Volker R.W. TI - 9MeV Electron Irradiation on Nb Samples and 1.3GHz SRF Cavity J2 - Proc. of SRF2021, East Lansing, MI, USA, 28 June-02 July 2021 CY - East Lansing, MI, USA T2 - International Conference on RF Superconductivity T3 - 20 LA - english AB - To enhance bulk Nb RF cavity performances at high accelerating field it is important to prevent precipitates formation. Doping and heat treatments can mitigate such effect and the most accredited theory is based on the presence of proximity-coupled niobium hydrides [*]. Irradiation can induce vacancy-2H complexes [**] and in this study, the effects of 9MeV electrons on Nb samples and cavity up to fluences of 1.8x1021e/m2 are investigated. The size and density changes of micro-hydrides before and after irradiation was measured by cryo-laser confocal microscopy and a new analytic technique based on computer vision has been used. A strong reduction in hydrides size was found after irradiation and the hydrides formation temperature was shifted to lower values suggesting a reduction in both the activation energy barrier and the critical radius. We conclude that electron irradiation can indeed prevent the formation of large hydrides in H-loaded Nb bulk sample. 1.3GHz Nb cavity has also been submitted to electron irradiation treatment in stationary mode and Q vs E curves and T-map measurements before and after irradiations recorded the changes induced by radiation on cavity performance. PB - JACoW Publishing CP - Geneva, Switzerland ER -