EVS-EN 61788-2:2007

This part of IEC 61788 covers a test method for the determination of the d.c. critical current of Nb3Sn composite superconductors which are fabricated by either the bronze process or the internal tin diffusion process and have a copper/non-copper ratio larger than 0,2. This method is intended for use with superconductors which have critical currents of less than 1 000 A and n-values larger than 12 under standard test conditions and at magnetic fields of less than or equal to 0,7 times the upper critical magnetic field. The test specimen is immersed in a liquid helium bath at a known temperature during testing. The Nb3Sn composite test conductor has a monolithic structure with a total round-cross-sectional area that is less than 2 mm2. The specimen geometry used in this test method is an inductively coiled specimen. Deviations from this test method which are allowed for routine tests and other specific restrictions are given in this standard.