Progress in the design and operation of high-Tc coils using dip-coat BSCCO-2212/Ag tape

The authors describe a continuing industry/university collaboration to develop the next generation of high-field superconducting magnets for research purposes. The use of high-temperature superconductors is necessary to overcome the limited critical fields of their low temperature counterparts, however engineering problems associated with these materials are still not fully resolved. Their unique variant on the wind, react and tighten (WRAT) approach using dip-coated BSCCO-2212 on Ag substrate results in extremely high filling factors and engineering current densities (in excess of 150 A/mm² at 4 K), as well as overcoming the problem of minimum bending radius associated with react and wind technology. The method has now been perfected and single pancakes have added 275 mT to 16 T in a 40 mm bore at 4 K. A cryocooled single pancake achieved 490 mT at 20 K with an engineering current density of 57 A/mm².