IPN, Orsay
Bulk niobium cavities have quite reached their maximum performances. Maximum accelerating field reached is above 35-40 MV/m on a multi-cell cavity at 1.8 Kelvin and it is reasonable to achieve 25-30MV/m with high reliability. The question of increasing the accelerating gradient in a significant way is runnig regarding the huge amount of units required for new projects (16000 units for ILC). A promissing solution is to use thin films of new materials deposited on copper or niobium. In order to investigate the behaviour of these materials for the accelerating cavities, we have delopped a dedicated setup based on thermometric methode and a TE011 cavity. We present here the design of the setup, the cavity design and the sensitivity of the method expected for the surface resistance measurement of materials under RF field.
