On the global and local mechanical stability of the LHC

The Large Hadron Collider (LHC) will be the first CERN accelerator entirely operating in superfluid helium below 2 K. The superconducting magnets and their interconnections constitute a discontinuous, nearly 27 km long, pressure vessel, subdivided in 8 octants. The main dipole and the quadrupole magnets are elastically supported in the LHC Arc Cryostat System and will be subjected to considerable interconnection forces when cooling down the LHC. The present note addresses the problem of mechanical stability of the LHC both on the global and on the local level. In both cases, a bifurcation buckling analysis has been carried out and the corresponding safety factors were assessed.