20 T dipoles and Bi-2212: the path to LHC energy upgrade
  Increasing the energy of the LHC would require a ring of \sim20 T magnets using the superconductors Nb3Sn and Bi-2212/Ag. The technology for Bi-2212/Ag wire, cable, and coil has advanced significantly but is still far short of the performance needed for such magnets. New technol-ogy for both wire and cable is under development, which if successful would yield the needed performance. 
P.M. McIntyre, K. Damborsky, E.F. Holik, F. Lu, A.D. McInturff, N.   Pogue, A. Sattarov, E. Sooby (Texas A&M University, Col...
physics.acc-ph