Multilayers Activities at Saclay / Orsay

In the investigations on the high gradient SRF cavities, the superconducting multilayer is a promising alternative. The predictions show that SIS nanocomposite (Superconductor/Isolator/Superconductor) could improve the efficiency limited by the bulk Nb itself used today for accelerating cavities. We started, at the IPNO lab incollaboration with the CSNSM lab (CNRS) and Irfu lab (CEA), an experimental study to test the screening effect on multilayer assemblies. Based on 3rd harmonic magnetometer and a TE011 SRF cavity, measurements of first critical magnetic field HC1 and surface resistance of samples have been performed. These promising results are the starting point of the MBE deposition developments. This setup is devoted to optimize the best organization of the multilayer to produce the model sample, and to find, in a close future, a realistic solution to apply this technique on an accelerating SRF cavity.