On the Feasibility of a Tripler Upgrade for LHC

The design of high-field dipoles has been optimized using a block coil geometry. The optimization includes stress management and flux plate suppression of multi-poles from snap-back. The design has been extended to higher field by devising a hybrid coil geometry containing inner windings of Bi-2212 and outer windings of Nb3Sn. A 24 Tesla dual dipole using this design offers the possibility of an LHC tripler. Issues of fabrication technology and synchrotron radiation control are discussed. There is no obvious upper limit to the field that could be attained for the dipoles of future hadron colliders.