Method for producing a superconductive element

Method for producing a superconductive element to be used as a wire-in-channel superconductor in magnetic resonance imaging (MRI) and in nuclear magnetic resonance (NMR) applications, comprising the steps of:

• providing a superconductive wire and a copper component having a longitudinal groove;
• positioning the superconductive wire in the groove;
• creating mechanical contact with at least one contact surface between the superconductive wire and a wall of the groove in the copper component;
• deforming to produce an intimate contact between the at least one contact surface;
• annealing the deformed superconductive wire and copper component at a temperature higher than the solidus temperature of a lead free solder material to achieve a metallic or intermetallic interface between the wire and the wall or the walls of the groove;
• wherein the at least one contact surface is coated with the lead free solder material before having the mechanical contact;
• wherein the lead free solder material is in contact with the superconductive wire;
• wherein the lead free solder material is a tin based alloy;
• wherein the tin based alloy is a binary alloy of tin-bismuth in which the bismuth content is 20 to 60% by weight;
• and
• wherein the binary alloy of tin-bismuth is alloyed with one or two components from the group of copper, silver, zinc, antimony and indium so that the content of each alloyed component is 0.1 to 20% by weight and the rest being tin or tin and impurities.