ADVANCES IN SUPERCONDUCTING RF CAVITY STIFFENING BY THERMAL SPRAYING

Mechanical stability of SRF cavities is an important issue for future pulsed high-energy e+/e- colliders like TESLA or for high intensity proton linacs using SRF cavities. The French collaboration IPN/LAL/CEA is studying since 3 years now a new stiffening method based on the addition of a copper layer on the cavity outer walls by thermal spraying. Several 3 GHz and 1.3 GHz prototypes have already been realized and prove the feasibility and interest of the technique. Numerical simulations have been performed to study the mechanical and thermal behaviour of this bimetal cavity to define the characteristics needed for the copper coating. Different thermal spraying methods are now investigated by means of mechanical and thermal characterization of sample and also by prototypes cavities RF tests in order to reach the best coating properties suitable for SRF cavities.