Stabilised superconductive tube for waveguide - has perforated zone at end covered with conductive layer by selective coating and etching

摘要

The method of forming a superconductive cable or waveguide uses a length of tube (1) with a layer of stabilised material on it outside (e.g. copper of aluminium) and an intermetallic binding substance inside. Part of the stabilising material is etched away then a blocking layer (4) of e.g. tantalum is applied to part of the exposed surface. Holes (5) which slope at an angle to the surface are made through the tube within the remaining part, by e.g. electroerosion. Thewholeexposed region is covered with a conductive coating (9) by using a bath of the molten metal, so that the inside surfaces of the holes and the adjacent regions are covered, in a diffusion process. Two ends treated in this manner can then be joined after heat treatment and after a sealing layer has been applied to the interior, and also after the blocking layer has been etched away from each end. An additional superconducting outer layer is then added.