  REBCO tape has remarkable performance for super-conducting technology, but it
is extremely expensive and it is a strongly anisotropic superconductor. The
design of a 3.5 T collider dipole is presented in which all turns of the body
winding are oriented so that the all turns of REBCO tape operate with maximum
current density. Each turn within the winding contains a stack of Cu-clad REBCO
tapes; all tapes within the turn are compressed to provide low-resistance Cu-Cu
contact, but the successive turns are electrically isolated. Each turn is
oriented so that the local magnetic field at the tapes is closely parallel to
the tape surface. Sextupole is controlled using a current-programmed turn to
provide excellent homogeneity over a 20:1 dynamic range. Issues of current
re-distribution during ramping, quench stability, AC losses, synchrotron
radiation, and cryogenics have been considered, and appear to provide favorable
properties for an ultimate-energy hadron collider.
