  A hadron collider operating at an energy much larger than the LHC ("HE-LHC")
would be a logical successor to the LHC itself, especially if its cost can be
minimized by reusing a significant part of the CERN infrastructure like the
existing tunnels and/or accelerators. The injector complex must however be
extended to reach a beam energy of ~1.2 TeV and. in view of the time span of
the HE-LHC project, the replacement of ageing accelerators can also be
necessary. The main possible options are outlined together with their
specificities.
