ENERGY DEPOSITION STUDIES FOR FAST LOSSES DURING LHC INJECTION FAILURES

Abstract Several instances of injection kicker magnet (MKI) failures have occurred in the first years of LHC operation, leading to misinjections or to accidental kicks of circulating bunches. In a few cases, MKI modules imparted a partial or an increased beam deflection, resulting in grazing bunch impact on beam-intercepting devices and consequently leading to significant secondary showers to downstream accelerator elements. In this study, we investigate different failure occurrences where miskicked bunches were incident on the injection beam stopper (TDI) and on one of the auxiliary injection collimators (TCLIB), respectively. FLUKA shower calculations were performed to quantify the energy deposition in superconducting magnets. Different sections of the LHC insertion regions 2 and 8 were studied, including separation dipole and inner triplet downstream of the TDI as well as matching section and dispersion suppressor adjacent to the TCLIB. The obtained results are evaluated in view of quench and damage limits