Speaker
Description
Nb₃Sn is a promising alternative to bulk Nb for superconducting radiofrequency (SRF) cavities due to its higher critical temperature (Tc ~18.3 K) and superheating field (Hsh ~400 mT), enabling improved cryogenic efficiency. Nb₃Sn coating method for superconducting radiofrequency (SRF) cavity has been developed following co-sputtering of Nb-Sn composite target using a DC cylindrical sputter coater. Deposition parameters and annealing strategies were optimized for uniform Nb₃Sn coating. 1.5 µm Nb-Sn film was deposited onto 2.6 GHz Nb SRF cavity and annealed at 600°C for 6 h, followed by 950°C for 1 h. Cryogenic RF testing confirmed Nb₃Sn formation with Tc = 17.8 K. A post-annealing light Sn recoating process improved the cavity’s performance, achieving Q₀ = 8.5 × 10⁸ at 2.0 K.
