CERN/LHCC 2002-036
LHCC 60
24 October 2002
 
 

LARGE HADRON COLLIDER COMMITTEE

Minutes of the sixtieth meeting held on

Wednesday and Thursday, 2-3 October 2002




OPEN SESSION:

1.    ATLAS Physics Programme for the First LHC Run: F. Gianotti / CERN

2.    CMS Physics Programme for the First LHC Run: D. Denegri / CEA-Saclay

3.    Status Report on the LHC Computing Grid Project: L. Robertson / CERN
 

CLOSED SESSION:

Present:     S. Bertolucci, M. Bruzzi*, M. Calvetti (Chairman), R. Cashmore, A. Ceccucci, J. Dainton, F. Ferroni,
                  D. Froidevaux*, J.-J. Gomez-Cadenas, M. Hauschild, H. Hoffmann*, M. Jaffre, Y. Karyotakis, B. Löhr,
                  M. Mangano, P. Messina*, J. Nash, J. Panman, K. Potter, L. Robertson*, W. von Rueden, P. Seyboth,
                  H. Tiecke, K. Tokushuku, E. Tsesmelis (Secretary), C. Vallée, I. Videau* (representing D.Schlatter),
                  V. Vuillemin* (representing D. Schlatter)
 

                                                                        *) Part timeApologies: D. Cassel
  1.          INTRODUCTION 2.       REPORT FROM THE DIRECTOR FOR COLLIDER PROGRAMMES


3.       REPORT FROM THE ALICE REFEREES

4.       REPORT ON THE ATLAS INSTALLATION REVIEW 5.       REPORT ON THE CMS INSTALLATION REVIEW 6.       DISCUSSION ON THE RPC DETECTORS The LHCC discussed the study comparing the ATLAS and CMS RPC detectors as detailed in the submitted report LHCC 2002-031 / G-011. The purpose of the study was to describe the different designs of the ATLAS and CMS RPCs in an effort to understand the different working parameters of the two detectors.

The conclusions of the study indicate that the different working parameters of the two types of RPCs are for the most part now understood and arise from (a) different normalizations to standard temperature and pressure, (b) the inclusion of SF6 gas in the ATLAS but not in the CMS chambers, and (c) the one-gap (ATLAS) versus two-gap (CMS) configurations.

Ageing tests at the Gamma Irradiation Facility (GIF) are continuing and the Committee underlines the importance of successfully completing these tests. Due account of the requests for ageing tests of several final RPC detectors at the GIF should be taken in the GIF schedule.

Finally, it was concluded that, as in the case of ATLAS, streamers at voltages moderately above the efficiency plateau knee were not observed in the CMS RPCs.
 

7.       REPORT FROM THE ATLAS REFEREES The LHCC heard a report from the ATLAS referees, concentrating on follow-up issues from the recent Comprehensive Review and the status of the TRT.

Good progress was reported on the LAr, Tile, and Hadronic End-cap Calorimeters. Concerning the Electromagnetic End-cap Calorimeters, problem areas have been encountered with the electrodes, spacers and stacking. Although the final stacking has started, the LHCC considers that it is too early to draw conclusions on any delays in the schedule and will continue monitoring the progress. Moreover, the End-cap C cryostats have exhibited a problem with the spacers between the warm and cold vessels that will require repair. The resulting delay is expected to be recovered and not to affect the overall ATLAS schedule. Significant progress was reported on the negative low voltage regulators, with several hundred samples expected at CERN in November 2002.

The LHCC heard a report on the status of the glass wire-joint problem in the TRT resulting from the reaction of the Xe/CO2/CF4 gas with the wire joint. The TRT group has continued investigating alternative gas mixtures and is now ready to move to a new baseline gas Xe/CO2/O2 coupled with a CF4-based cleaning gas. However, the LHCC noted that the new gas has not yet been completely validated as tests with the final closed gas system and irradiation studies will only be completed in at most two years. Nevertheless, the TRT group has decided to resume construction of the straw tubes while the final validation tests are performed. The Committee expressed its concern as a definitive solution has not yet been confirmed and will continue monitoring the progress closely.

Finally, the LHCC referees received a document on the ATLAS RPC Quality Control.
 

8.       REPORT FROM THE LHC COMPUTING GRID PROJECT REFEREES The Committee heard a report from the LHC Computing Grid (LCG) Project referees.

Following the written submission and the first discussion in the LHCC Closed Session in July 2002 of the LCG proposal for the construction of a prototype LHC computing system, the LHCC referees had several discussions with the LCG Project team, and the Project was presented to the Open Session of the LHCC meeting in October 2002 as well as being discussed with the LCG group in the corresponding LHCC Closed Session.

The Committee considers that Phase 1 of the LCG Project is a necessary step towards the construction of the LHC computing system. The execution of the Project requires the immediate deployment of the organisation structure and of the basic infrastructure necessary for the realisation of the LHC computing network.

To this end, the use of GRID tools, the collaboration of the many Regional Computing Centres, including CERN, and the coherent development of the common software tools used by the four LHC experiments, are essential components of the project. The construction at CERN of the Tier-0 prototype allows CERN to play a central contributing role to the Project and the Committee encourages the realisation of the Tier-0 prototype at CERN.

Moreover, the construction of an appropriately sized and technologically advanced computing center, with links to the Regional Computing Centers through the Grid technology, is considered to be a necessary step in designing Phase 2 of the LCG Project, which must be ready in 2007.

The LHCC considers the LCG Project team to be very well organised and competent to undertake the task. The Steering Committee (SC2) and the Project Execution Board (PEB) of the Project, the identified objectives, and the participation of the Regional Computing Centres to the definition of the projects and in the decision making process, constitute the basis for a successful initiative.

The LHCC strongly supports the LCG Project as it considers the initiative to be a very important strategic step toward the success of the LHC computing. The Committee will continue monitoring the project in the future.
 

9.       CMS COMPREHENSIVE REVIEW 10.      REPORT ON THE CMS ADDENDUM TO THE ECAL TDR 11.      ALICE ADDENDUM TO THE TIME-OF-FLIGHT TDR 12.      REPORT FROM THE LHCb REFEREES 13.      REPORTS ON THE ALICE, ATLAS AND CMS COMPLETION COSTS 14.     REPORT FROM THE RD50 REFEREE 15.     TEST BEAMS The SPS and PS Coordinator reported on the status of the test beams.

He summarised the test beam activities of the LHC experiments at the SPS and PS, including the prolongation of the SPS proton run by 8 days, and noted that the SPS beam time in 2002 was sufficient and used efficiently.

The draft of the 2003 PS and SPS schedules were presented. The SPS Fixed Target Programme starting on 19 May consists of 1 week of LHC-type bunched beams and a 15-week nominal proton run. The proton run will end on 7 September and will be followed by a 5.5-week Indium run. The exact schedule of the LHC-type beams has not yet been decided. The PS machine schedule is similar to 2002 and will run for a total of 171 days.

The LHCC stressed the importance of taking due account of the requests for ageing tests of several final RPC detectors at the Gamma Irradiation Facility (GIF).
 
 

16.     DATES FOR LHCC MEETINGS Dates for 2002:                                    27-28 November

             Dates for 2003:

                                    29-30 January

                                    26-27 March

                                    21-22 May

                                    2-3 July

                                    24-25 September

                                    26-27 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
                               janet.grant@CERN.CH