LHC Operational Experience of the 6.5 TeV Proton Run with ATS Optics

Mirko Pojer, Markus Albert, Reyes Alemany-Fernández, Theodoros Argyropoulos, Enrico Bravin, Andrea Calia, Guy Crockford, Stephane Fartoukh, Kajetan Fuchsberger, Rossano Giachino, Massimo Giovannozzi, Georges-Henry Hemelsoet (+14 others)
In May 2017, the CERN Large Hadron Collider (LHC) restarted operations at 6.5 TeV using the Achromatic Telescopic Squeeze (ATS) scheme with a target beta-star of 40 cm in ATLAS and CMS. The number of bunches was progressively increased to a maximum of 2556 with emittances of 2.5 um. In August, several machine parameters had to be re-tuned to mitigate beam loss induced instabilities and maintain a steady increase of the instantaneous luminosity. The use of a novel beam type and filling pattern
more » ... d filling pattern produced in the injectors, allowed filling the machine with very low emittance beam (1.5 um) achieving an equivalent luminosity with 1868 bunches. In September, the beta-star was further lowered to 30 cm (using, for the first time, the telescopic technique of the ATS) and the bunch intensity pushed to 1.25·10¹¹ protons. In the last 3 months of 2017, the LHC produced more than 500 pb-1 of integrated luminosity per day, delivering to each of the high luminosity experiments 50.6 fb-1, 10% above the 2017 target. A general overview of the operational aspects of the 2017 proton run will be presented.
doi:10.18429/jacow-ipac2018-mopmf050 fatcat:vvgqbei4wfcvddtez27jzl42ae