Title: Maximum screening fields and the optimum parameters of superconducting multilayers for resonator cavities
Author: Alex Gurevich
Institution: Old Dominion University
Abstract: Alex Gurevich, It is shown that multilayer coating can screen the applied field above the superheating fields of both the superconducting layers and the Nb substrate. There is an optimum multilayer thickness for which the breakdown field at which the multilayer remains in the vortex-free Meissner reaches maximum. It is shown that a dirty layer about the London penetration depth thick at the non-structured Nb surface can increase the superheating field of up to 290 mT. Growing optimized multilayer structures of Nb3Sn or iron pnictides or forming a dirty layer at the surface of the Nb resonator cavities for particle accelerators offer opportunities to increase the peak accelerating electric fields above 100 MV/m.