Arc suppression snubbers for the energy extraction switchgear in the superconducting main circuits of the LHC Collider: Impact on the safety-critical quench protection system

A major challenge for operating a quench protection system for a chain of superconducting magnets and their interconnecting busbars is posed by the mandatory coexistence between the ultrasensitive and fast quench detectors and the high power systems, such as the power converter and the switchgear of the energy extraction (EE) facilities with their regular, occasionally violent, actions on the circuit elements. The eight, 13 kA, main dipole powering circuits of the recently inaugurated LHC Hadron Collider at CERN represents such circuits, for which a number of mitigation features has been designed and implemented in order to facilitate this coexistence.