Performance tests of Bi-2212 insert magnets fabricated by Ag sheath method and dip-coating method

摘要

We have fabricated small magnets using Bi-2212/Ag tapes prepared by the combination of a powder-in-tube method or a dip-coating method and a wind-and-react method. The magnets were inserted in a 21 T superconducting magnet and tested under various bias fields at 4.2 K. All of the magnets could sustain large electromagnetic force under high magnetic fields, and no damage was introduced during the test. Critical current density of a magnet consisting of 4 double pancake coils was 9.5/spl times/10/sup 4/ A/cm/sup 2/ in 21 T which corresponded to the central generated field of 1.76 T. Thus the total field of 22.76 T was attained in a full superconducting state. No degradation of superconducting properties was produced by a thermal cycle and moisture in air.