16 L 2 : Operation , observations and physics aspects

Events linked to fast losses in the LHC half-cell 16L2 have plagued a large part of the 2017 run. While a detailed analysis of what happened is treated at the LHC Performance Workshop (Chamonix 2018), this contributionwill gather the available observations and the understanding of the situation as predicted by simulations and models, before the warm-up during the 2017 year-end technical stop (YETS). The impact of the 16L2 events on the global LHC performance in 2017 will also be evaluated.