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Summary of Session 1 'Lessons from 2011'

Abstract

Review of 2011 LHC Run from The Experiments Perspective, M. Ferro-Luzzi (PH-LBD): M. Ferro-Luzzi highlighted the excellent performance of the machine and the experiments in 2011 and the fast and impressive achievements both when operating with protons and Pb ions. In a month the same luminosity as during the full 2010 proton run was delivered, and a factor 16 higher luminosity was produced with Pb ions. The excellent machine performance allowed ATLAS and CMS to make interesting observations in the context of the Higgs’ boson search and LHCb found some evidence of CP violation in time-integrated D0 which could open the way for a new physics. Input from Evian, M. Lamont (BE-OP): M. Lamont presented a summary of what discussed in Evian about lessons learnt during 2011 operation and improvements foreseen for 2012. He underlined that 2011 was a remarkable year with a continuously faster increase in luminosity production and without real show stoppers. The machinewas characterized by operational robustness, a good reproducibility, stability, beam lifetime, optics control and an excellent performance of the Machine Protection system (MPs) and of the injectors. The 2011 Run: Availability Analysis, A. Macpherson (BE-OP): A. Macpherson spoke about machine availability in 2011 and gave  More>>
Authors:
Lamont, M; Bracco, C [1] 
  1. European Organization for Nuclear Research, Geneva (Switzerland)
Publication Date:
Jul 01, 2012
Product Type:
Conference
Report Number:
CERN-2012/006
Resource Relation:
Conference: Chamonix 2012 Workshop on LHC Performance, Chamonix (France), 6-10 Feb 2012; Other Information: Country of input: International Atomic Energy Agency (IAEA); DOI: 10.5170/CERN-2012-006.7; Copyright (c) 2012 CERN; This is an open access publication distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.; Related Information: In: Proceedings of Chamonix 2012 Workshop on LHC Performance| by Carli, C (ed.) [European Organization for Nuclear Research, Geneva (Switzerland)]| CERN - European Organization for Nuclear Research, Geneva (Switzerland)| 403 p.
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CERN; CERN LHC; LECTURES
OSTI ID:
22538205
Research Organizations:
CERN - European Organization for Nuclear Research, Geneva (Switzerland)
Country of Origin:
CERN
Language:
English
Other Identifying Numbers:
Other: ISSN 0007-8328; ISBN 978-92-9083-378-9; TRN: XC16A0657109185
Availability:
Available on-line: http://cds.cern.ch/record/1492167/files/MLCB_0_01.pdf; Available on-line: http://cds.cern.ch/record/1424362/files/CERN-2012-006.pdf
Submitting Site:
INIS
Size:
page(s) 7-11
Announcement Date:
Dec 03, 2016

Citation Formats

Lamont, M, and Bracco, C. Summary of Session 1 'Lessons from 2011'. CERN: N. p., 2012. Web.
Lamont, M, & Bracco, C. Summary of Session 1 'Lessons from 2011'. CERN.
Lamont, M, and Bracco, C. 2012. "Summary of Session 1 'Lessons from 2011'." CERN.
@misc{etde_22538205,
title = {Summary of Session 1 'Lessons from 2011'}
author = {Lamont, M, and Bracco, C}
abstractNote = {Review of 2011 LHC Run from The Experiments Perspective, M. Ferro-Luzzi (PH-LBD): M. Ferro-Luzzi highlighted the excellent performance of the machine and the experiments in 2011 and the fast and impressive achievements both when operating with protons and Pb ions. In a month the same luminosity as during the full 2010 proton run was delivered, and a factor 16 higher luminosity was produced with Pb ions. The excellent machine performance allowed ATLAS and CMS to make interesting observations in the context of the Higgs’ boson search and LHCb found some evidence of CP violation in time-integrated D0 which could open the way for a new physics. Input from Evian, M. Lamont (BE-OP): M. Lamont presented a summary of what discussed in Evian about lessons learnt during 2011 operation and improvements foreseen for 2012. He underlined that 2011 was a remarkable year with a continuously faster increase in luminosity production and without real show stoppers. The machinewas characterized by operational robustness, a good reproducibility, stability, beam lifetime, optics control and an excellent performance of the Machine Protection system (MPs) and of the injectors. The 2011 Run: Availability Analysis, A. Macpherson (BE-OP): A. Macpherson spoke about machine availability in 2011 and gave some statistics of fills for p-p and Pb-Pb runs. He calculated a machine availability of 76.7% and that 33% of the operation time was spent in stable beam. The Hubner factor, which gives an estimate of the luminosity production duration, was slightly bigger than the expected 0.2 value both for the proton (0.22) and lead ion (0.24) runs. Stable beams lasted in average ∼6 hours but about 50% of the fills were shorter than 4 hours. Injection and Lessons for 2012, C. Bracco (TE-ABT): C. Bracco made a presentation on the performance of the injection system. The injection of 144 bunches became fully operational in 2011 in agreement with what predicted during the last Chamonix workshop. Moreover 288 bunches could be injected, during MD time, for both beams with a good margin between the losses and the BLM dump thresholds. Improvements are still needed to optimize the 25 ns beam in the injector chain and accumulate it in the LHC with a good lifetime; the results are encouraging in view of operation with the designed intensity. Machine Protection, M. Zerlauth (TE-MPE): M. Zerlauth introduced the architecture of the LHC Machine Protection System (MPS). He explained that this is a complex system that checks more than 10000 interlock conditions and has to evolve to follow operational changes, special runs and MD requirements. Vacuum Performance and Lessons for 2012, V. Baglin (TE-VSC): V. Baglin presented a talk on the main vacuum observations made in 2011: dynamic effects induced by the circulating beam (synchrotron radiation and e-clouds) and unexpected local pressure spikes. He explained that the desorption yield in the cold-warm transitions was much worse (factor 50) than in the warm-warm transition due to gas load from the cold part. Emittance Preservation, V. Kain (BE-OP): V. Kain spoke about emittance preservation all along the injectors chain up to collisions in the LHC. She explained that injectors behaved extremely well in 2011 and, for the 50 ns beams and a bunch population higher than nominal, an emittance blowup of 0.4 μm was measured from the PS to the SPS (from design report: 0.5 μm were estimated for 25 ns beams). On the other hand a 20-30% emittance growth is observed between the SPS flattop and LHC collisions. Several methods are used for emittance measurements (wire scanner, BSRT and luminosity) and all methods present some limitations. Moreover measurements in the SPS and in the LHC are not synchronized and refer to different beams.}
place = {CERN}
year = {2012}
month = {Jul}
}