HE LHC review

Conferences and Workshops
Category ID: 
11 Dec 2017 - 08:30 to 12 Dec 2017 - 17:00

The HE-LHC should deliver proton-proton collisions a centre-of-mass energy of 27 TeV with an integrated luminosity of 10-20/ab over 20 years. The HE-LHC is based on the 16 Tesla dipole magnets developed for the FCC-hh. The LHC tunnel will be unchanged. Therefore, the present LEP/LHC tunnel and the existing LHC infrastructure constrain the optics footprint of the HE-LHC. The curvature of the arcs is fixed and so are the straight sections, i.e. the lengths of the experimental insertions, collimation sections, and extraction straight cannot be scaled with energy as it has been done for the FCC-hh. On the other hand, the available space in these insertions may shrink if the strengths of dipoles and quadrupoles cannot be raised in proportion to the energy. Another challenge appears at injection, where the HE-LHC physical aperture is reduced compared with the LHC aperture, due to the smaller bore of the high-field magnets, and due to the expanded dimensions of the FCC-hh type beam screen, whereas the values of the optical functions increase from those of the LHC. The related choice of injection energy, the injector design, and the transfer lines are other important aspects for the HE-LHC.

At the December meeting, the HE-LHC design baseline should be reviewed in view of its presentation in the FCC Conceptual Design Report. Possible showstoppers or improvement measures should be identified.

Review goals and charge: 
  1. review the HE-LHC parameters 
  2. review the arc optics design choice including physical and dynamic aperture
  3. review the experimental IR optics and the proposed shielding 
  4. review the optics design and performance of the collimation systems, including machine protection aspects for injection errors and asynchronous beam dump
  5. review the optics for the injection and extraction straights 
  6. review the optics for the remaining straight sections, e.g. LSS4 (beam instrumentations and transverse damper)
  7. review the overall lattice integration 
  8. review the optimum injection energy, injector choice, and transfer lines
  9. review the single-beam stability, including impedance effects and Landau damping 
  10. identify any areas with optimization potential and important missing items or considerations and propose high-priority actions towards the completion of the CDR baseline configuration

The panel of reviewers will be composed of: Ralph Assmann (DESY), Oliver Brüning (CERN), Yunhai Cai (SLAC), Stephane Fartoukh (CERN), Daniel Schulte (CERN), Andrei Seryi (JAI Oxford), Vladimir Shiltsev (FNAL), Jorg Wenninger (CERN).