Method for producing a superconducting magnet coil

A process for producing a superconducting magnet coil which comprises the steps of:

• (a) winding a composite superconductor comprising a plurality of thin superconducting wires and a stabilizer selected from the group consisting of copper and aluminum which stabilizer is thermally or electrically contacted with the wires to form a coil,
• (b) filling the gap between coils of the composite superconductor with a curable resin composition having a viscosity of 0.01-10 poises at the time of filling and comprising (i) at least one epoxy resin selected from the group consisting of diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F and diglycidyl ether of bisphenol AF, all having a number-average molecular weight of 350-1,000, (ii) a flexibilizer, and (iii) a curing catalyst, to obtain a curable-resin-composition-impregnated coil, and
• (c) heating the curable-resin-composition-impregnated coil to cure the composition,
• the step (a) including subjecting the composite superconductor to surface treatment with a coupling agent before winding the composite superconductor.