Summary notes of the LCU meeting on 02/08/2011

Present: CA, HB, RC, RDM, MF, MG, JJ, YL, EM

Report from meetings

• SLM and general information -> MG
  Welcome for Pascal Hermes who works over summer as a student with JJ on higher beta optics for ALICE.
  Office renovation will proceed in blocks of six offices. the exact schedule is not know. We are asked to leave our offices in a clean state without stacks of papers.
  There was a mini Chamonix meeting in July on the planning of the second part of the proton running this year:  stay with 50 ns bunch spacing, profit from the low emittance possible from the injectors available with double batch injection in the booster and increase the bunch intensity. Beta* reduction down to 1 m would be possible and maybe tested later in the year. With the help of Thys, the optics files were improved and can be found in the optics database in subdirectory new_ip.._squeeze.
  The peak luminosity in the LHC exceeded 2.e33cm-2s-1. Fills are often lost for various reasons including UFOs and SEUs.
  We had an MD block since our last meeting and a 90m study just before the MD block. The MD studies and in particular also the optics related studies (ATS, 90 m) went very well. Non-linearities and the dynamic aperture was measured and the analysis in progress. Beam-beam studies showed that the head-on beam-beam tune shift can be roughly 5 times higher than for the LHC design. Parasitic beam-beam effects were found to be about as expected. Together, this allows to increase the luminosity by using smaller emittances and higher bunch intensities.
  The LHC at home servers are moved from the UK Queen Mary university to CERN.
  This afternoon we will have an LEB meeting (attended by MG and HB) on the smaller beam pipe for CMS to be installed in the next longer shutdown (LS1) similar to what has already been agreed for ATLAS. ALICE may also request a smaller experimental beam-pipe.
  For the ion running, ALICE requests a small beta *  = 1.5 m. MG ask to check whether the optics are ready.
  JJ said that LHCb considered for a moment to also request heavy-ion collisions but did not request this as their detector is not well suited for the high multiplicities for heavy ion collisions.

IBS and luminosity evolution with higher harmonic RF -> TM
Postponed to the next meeting.

AOB

After the summer period we will go back to the usual two weeks scheduling of this meeting alternating with the FiDeL meetings.

Last update: 03-August-2011

MG & HB

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