Improving the stability of pulse superconducting radio frequency cavities by the construction of an Al–Nb double layer structure

Superconducting Radio Frequency technologies are widely employed in particle accelerators to explore the frontiers of science. Pure niobium cavity with 2.8–4[Formula: see text]mm thickness is the traditional technology of a compromise between the thermal conduction and mechanic stability. To meet the requirements of the higher stability of accelerators such as ADS linac, high intensity pulse linac, a solution for enhancing the stability of superconducting cavities by the Al–Nb double layer structure is proposed while maintaining enough heat transfer capacity. In this work, a 3.9[Formula: see text]GHz single cell Al–Nb elliptical cavity was fabricated to validate this proposal. During the vertical testing, the cavity shows a significant enhancement in the mechanical stability with LFD coefficient reduction by 88% compared to the pure Nb cavity and [Formula: see text] value is kept at the same level. Additionally, the basic parameters of Al–Nb composite material were tested and reported as well.