During LS1 most machine protection systems (MPS) have undergone significant changes. A full (re-) commissioning of the MPS has been performed before and respectively during beam commissioning in 2015, followed by a step-wise intensity ramp-up to reach nominal beam intensities. This contribution will summarize the results of the MPS commissioning and the intensity ramp-up, focusing on issues...
During 2015, injections of 144 bunches into the LHC induced losses of up to 88% of the dump thresholds on the TDI. During run 2 these losses were studied in greater detail with diamond based particle detectors. It was found that the main loss contribution is due to ghost bunches, originating from the SPS, swept over the TDI during the rise and fall time of the injection kicker magnet MKI. This...
In total, over 5700 changes to the BLM thresholds were made during 2015. The new thresholds are based on the operational experience from Run 1, on new simulation models and on results from quench tests performed so far. Following the first experiences with operation at 6.5 TeV, a series of adjustments were made throughout the first operational year of Run 2. An overview of the main changes...
LHC operation at 6.5TeV required major changes of the collimator BLM thresholds adopted in Run 1. At startup in 2015, the BLM thresholds at collimators were set by scaling the values in 2012 to 6.5TeV. This approach enabled a smooth commissioning during the intensity ramp up period. Throughout 2015, thresholds have been further optimized to allow for 200kW primary betatron losses, to...
This contribution reviews the status of three main beam instruments currently in use for machine protection purposes: the IP6 interlock BPMs, the Beam Current Change Monitor (BCCM) and the abort gap monitor (BSRA). Their performance during 2015 operation and observed limitations will be discussed as well as plans for future improvements and/or alternative solutions in order to allow for...