Description
Chairs: Mike Lamont, Chiara Bracco
As far as beam-losses are concerned, UFOs and the ULO have been the most prominent threats to machine availability in Run-2 proton operation. For the time being, the fast advance of the conditioning effect and the orbit bump around the ULO appear to have saved the day. In this presentation we will give an overview of beam losses in the LHC with protons and ions, the...
The brief experience with 25 ns beam in the LHC at the end of Run 1 suggested that the electron cloud effects were set to pose important challenges to the machine operation during Run 2. In spite of four weeks of dedicated scrubbing run, the 2015 proton run of the LHC fully confirmed this expectation, with the electron cloud severely degrading the beam quality at the...
Beam induced RF heating of several LHC devices represented a significant limitation before LS1. A lot of effort was invested by equipment groups to mitigate these issues and add monitoring to be able to react early. This effort clearly paid off in 2015 and most limitations could be waived. Bunch length could even be allowed to decrease below 1 ns during long fills without...
With the LHC operation at 6.5 TeV and with 25 ns bunch spacing after LS1, the understanding and control of beam instabilities in 2015 has become at least as challenging as during Run 1 and a crucial point to be followed to guarantee a smooth intensity ramp up. As expected, electron cloud appeared to be the dominant instability driver during the early phases of Run 2...
The LHC 2016 run will be a high intensity 25 ns physics production run. During the 2015 commissioning run several issues for the SPS and SPS-to-LHC transfer became apparent which will need to be addressed in 2016 and the years to come. Some of these will only be fully mitigated with the LIU upgrade of the SPS. This talk will summarize the experience with 25 ns beams in...
After summarizing the post-LS1 beam instrumentation performance, the presentation will focus on the key challenges for beam diagnostic systems in 2016. This will first concentrate on instruments that are essential for beam commissioning and operation, such as the BPM and tune systems for high sensitivity orbit and tune measurements. An overview will then be given of the...
A short update will be given about the activities being performed in the 2016-16 YETS by ATLAS and CMS. Particular focus will be given to activities on the critical path, notably the repair of the ATLAS End Cap Toroid Bellows, the cleaning of the CMS magnet cryogenic system and the diagnosis and repair of the water leak in the CMS end-cap.
