Electrodeposition of copper applied to the manufacture of seamless superconducting rf cavities

Niobium thin film coated copper superconducting radio frequency elliptical cavities have demonstrated for many years their strong potential as an alternative to bulk niobium cavities. The lower performance at high rf field is often attributed the defects observed in elaborated Nb layer, sometimes originated from inherited substrate itself. currently used methods of manufacturing substrates include several steps electron-beam welding order join half cells and cutoffs which can contribute porosities. Seamless are nowadays developed avoid decrease global cost We propose this study innovative route cavity formed by electrodeposition on a sacrificial aluminum mandrel. strength process relies total absence joints. Two different electroforming techniques using either direct current or pulsed plating been investigated. electroformed exhibited similar mechanical robustness, cryogenic properties purity oxygen-free copper. In addition, fabrication was validated test mandrels mimic geometry 1.3 GHz