Effect of Quench Heater and CLIQ Firing on the Circulating HL-LHC Beam

A small vertical orbit oscillation of the LHC beam was observed following a quench of a main dipole magnet. This effect was thought to be caused by the current dis-charged in the quench heater (QH) strips of the superconducting magnet and confirmed in dedicated experiments with beam in the LHC. Quench heater connection schemes with the largest effect have been identified for the LHC and its future HiLumi upgrade (HL-LHC). Furthermore, the impact on the beam following discharges of the Coupling-Loss Induced Quench (CLIQ) system, a novel technology to protect high current superconducting magnets in case of a quench, was studied to evaluate the possible failure cases.