JOINING METHOD FOR SUPERCONDUCTING THIN FILM WAVEGUIDE

摘要

PURPOSE:To decrease the surface defects by using a superconducting material equal to a superconducting thin film at least at the inner surface side of each joining part of a base material, forming a superconducting thin film on the inner surface as a waveguide, and joining the superconducting material parts of these waveguides to each other. CONSTITUTION:A niobium ring 2 is welded to each of both end faces of a copper columnar block having a prescribed size. Then both end face parts are formed into the large opening parts 3 with the center part narrowed into a small opening part 4 respectively with cutting. Thus a single cavity 5 is obtained and a niobium thin film 8 is formed on the inner surface of the cavity 5 by sputtering. Then the stepped projecting and recessed surfaces of the cavity 5 containing the film 8 are joined to each other, and electronic beam welding is applied to a contact part where both rings 2 touch with each other. Then these cavities 5 are joined together via a superconducting material in the form of a superconducting acceleration cavity.