CERN/LHCC 2004-005
27 January 2004



Minutes of the sixty-eighth meeting held on
Wednesday and Thursday, 28-29 January 2004



1.    TOTEM Technical Design Report: Karsten Eggert
2.    Report from the 9th Worskhop on Electronics for the LHC Experiments: Geoff Hall

3.    ALICE Status Report: Juergen Schukraft

4.    ALICE Trigger/HLT/DAQ/DCS/ECS Technical Design Report: Orlando Villalobos Baillie, Volker Lindenstruth,
       Pierre Vande Vyvre, Lennart Jirden, Sandro Vascotto

Present:     R. Aymar*, S. Bertolucci, K. Borras, M. Calvetti (Chairman), A. Ceccucci, J. Engelen,
                  L. Evans*, F. Ferroni, M. Hauschild, M. Jaffre, Y. Karyotakis, V. Kekelidze, Y.-K. Kim,
                 J. Knobloch, M. Mangano, J. Martin, P. McBride, S. Myers*, K. Potter, D. Schlatter, P. Seyboth,
                 H. Tiecke, E. Tsesmelis (Secretary), C. Vallée, T. Wyatt  Apologies: P. Seyboth

                                                                                                        *) Part time


    The minutes of the sixty-seventh LHCC meeting (LHCC 2003-068 / LHCC 67) were approved with the following modification: in point 15 (Reports on the Letter of Intent ó `Measurement of Photons and Neutral Pions in the Very Forward Region of the LHCí), the third paragraph is to be removed.

    The report from the LCG Project Comprehensive Review (LHCC 2003-065 / G-064) was approved without modification.


    The Chief Scientific Officer (CSO) informed the LHCC on various issues concerning CERN in general and the LHC Project in particular.

    He underlined the importance of the LHCC as a scientific committee in its role to review the LHC experiments and to serve as an advisory body. This position was reinforced by the Chief Executive Officer.

    The LHC Project Leader reported on the status of the LHC Machine. Installation of the machine has been hampered by delays in the cryoline installation in Sector 7-8. Discussions are presently underway with the contractor to find ways to speed up installation and re-scheduling of activities is in progress. The goal remains to close the LHC ring at the end of 2006 so that operation of the machine can commence in April 2007. Further information will be available in March once the cryoline installation in Sector 7-8 is fully underway. Moreover, as can be seen on the LHC Dashboard, construction and delivery of the main dipole magnets is progressing well.


The LHCC heard a report from the TOTEM referee, concentrating on reports concerning the TOTEM Technical Design Report and the TOTEM request for a Roman Pot test in the SPS ring.

The Committee heard a report on the refereeís preliminary reactions to the TOTEM Technical Design Report (LHCC 2004-002 / TDR 1). The Technical Design Report describes the method TOTEM proposes to use for the measurement of the total proton-proton cross-section and for the study of elastic scattering and diffractive dissociation at the LHC. The experimental set-up consists of two tracking telescopes T1 and T2 installed on each side of the interaction point to measure the inelastic proton-proton interactions in the forward region, and of two sets of silicon detectors in Roman Pots located symmetrically on each side of the interaction point to measure the elastic cross-section. (An additional Roman Pot station could be equipped later). The T1 telescope consists of five Cathode Strip Chambers while the choice between a Silicon Tracker and a tracker with GEM chambers is being considered for the T2 telescope. Finally, while the measurement of the total cross-section and elastic scattering can be performed using only the TOTEM detectors, the integration of TOTEM into the CMS detector offers the possibility of more detailed studies of diffractive events. The Committee encourages the TOTEM Collaboration to continue developing their experimental design and following further questions and discussions, the referee will make a full report on the TOTEM Technical Design Report at the next meeting of the LHCC.

The referee also reported on the TOTEM request to test the first Roman Pot prototype in the SPS ring in 2004. The referee addressed the outstanding issues from the previous LHCC meeting regarding the implications for the SPS schedule, operation parameters and vacuum, and the detailed plan of measurements TOTEM proposes to carry-out. In view of the resolution of the above open issues and due to the importance of the tests prior to the Roman Pot installation in the LHC, the Committee recommends approval of the tests and requested that the SPS & PS Physics Coordinator to allocate the requested beam time in the SPS schedule.

          4. TEST BEAMS The SPS and PS Physics Coordinator gave a report on the LHC test beams.

The first drafts of the 2004 PS East Hall and SPS user schedules have been released. The user requests have been allocated and some beam time is still free. The request for a 2-month neutron irradiation in the PS East Hall behind the DIRAC beam dump depends on the decision to be taken in either April or June on a DIRAC run in 2004. Discussions are ongoing to accommodate the ATLAS EMEC/HEC/FCAL and NA60 requests for beam time on the North Area H6 line of the SPS.

The Coordinator also reported on the request for a 3-day extension to the machine development period regarding the scrubbing studies in the SPS. The results of the studies carried-out in 2003 show that the scrubbing efficiency at cryogenic temperatures are lower than at room temperature. However, the uncertainties on the measurements on cryogenic surfaces are large and additional data is needed to better define the scrubbing scenario for the LHC. Recognising the importance of the scrubbing runs, the LHCC concurred with the requested 3-day extension to the studies.


The LHCC heard a report from Y. Muraki on the Letter of Intent to measure photons and neutral pions in the very forward region of the LHC. The aim of the experiment is to provide knowledge of the energy distribution of particles in the very forward region for the understanding of cosmic ray phenomena. The Collaboration proposes to install a scintillating fiber imaging calorimeter at a forward location about 140 m from an LHC interaction point, the choice of which has not been made. The calorimeter has the objective of identifying photons, and measuring individual photon energies above 100 GeV, the incident particle position and the two-photon invariant mass distribution showing a peak around the neutral pion mass.

The Committee noted that the requested beam conditions are similar to those required for the initial commissioning of the LHC machine in 2007.

The LHCC is reviewing the Letter of Intent and will provide its recommendation in spring 2004.

          6. REPORT FROM THE ATLAS REFEREES 10. DATES FOR LHCC MEETINGS                Dates for 2004: 24-25 March

12-13 May

30 June - 1 July

29-30 September

24-25 November

          The LHCC received the following documents:                                                                                                                 * Restricted circulation
  Emmanuel Tsesmelis
Eómail: LHCC.Secretary@CERN.CH
Tel. 78949, 164057
LHCC Secretariat: Janet Grant (Bldg. 14/4-022) Tel. 73424