Protection estimates for the 13 kA bus bars interconnections at 3.5 - 4.5 TeV

This memorandum provides alternate estimates of the critical additional resistance Radd of the 13 kA superconducting bus bars interconnections (IC), both for the LHC main bending (MB) dipole and main quadrupole (MQ) magnets. The calculations are performed using the 1-D thermo-electrical model described in [1], based on the definition of transverse local heat transfer coefficient towards the cooling helium bath established from the analysis of short sample tests performed in 2009 and 2010. Details on the model and its validation are not discussed here. The most pessimistic (adiabatic), most optimistic (full cooling) and most likely (partial cooling) critical additional resistances are provided, depending on the bus-bar and cable RRR, dump time constant, and space distribution of the defect, for beam energy between 3.5 and 4.5 TeV.