CERN/LHCC 2001-039
LHCC 55
22 November 2001
 
LARGE HADRON COLLIDER COMMITTEE

Minutes of the fifty-fifth meeting held on

Wednesday and Thursday, 21-22 November 2001








OPEN SESSION:

1.     Status of the LHC Machine: L. Evans

2.     Status of the LHC Computing Grid Project: L. Robertson

    CLOSED SESSION:
      Present: S. Bertolucci, M. Calvetti (Chairman), R. Cashmore, D. Cassel, A. Ceccucci, J. Dainton, A. Ereditato, F. Ferroni,
      J.-J. Gomez-Cadenas, M. Hauschild, M. Jaffre, J. Knobloch (representing M. Delfino), J. Lee-Franzini, B. Löhr,
      M. Mangano, J. May*, J. Nash, J. Panman, K. Potter*, P. Roudeau, D. Schlatter*, H. Schellman, H. Tiecke,
      K. Tokushuku, E. Tsesmelis (Secretary), C. Vallée, V. Vuillemin* (representing D. Schlatter).
       
                            *) Part time


      Apologies: Y. Karyotakis, P. Lebrun, L. Maiani, P. Seyboth, G. Zech.
       
       

      1. INTRODUCTION

      The Chairman welcomed the new members of the Committee, and thanked the retiring members for their vital role in defining the LHC experimental programme.

      The minutes of the fifty-forth LHCC meeting (LHCC 2001-031 / LHCC 54) and the LHCC report on the CMS Comprehensive Review were approved without modification.

      The Research Director for Collider Programmes reported on issues being currently considered to appraise the status of the LHC programme. The October sessions of the Resource Review Boards (RRBs) discussed the costs of the LHC experiments, including the costs to completion, Maintenance and Operation (M&O), and Commissioning and Integration (C&I). The RRBs authorized partially the M&O costs and will consider the remainder at subsequent sessions. The ATLAS and CMS costs to completion and the C&I costs, although accepted as necessary, are not yet approved. The RRBs asked the experiments to investigate ways to reduce their overall costs.

      He also stressed that the LHC Project is keeping to the existing, approved schedule and that only technical difficulties would provide a reason to change. Any revision to the schedule will not be made before March 2002. Currently, there are two main concerns: the procurement of the superconducting cable for the dipole magnets and the civil engineering at Point 5.

      Among other developments, a paper has been written and submitted to the Finance Committee and to the Committee of Council summarizing the extra costs to the LHC. Moreover, in an effort to improve efficiency and to identify opportunities for economy, 5 task forces have been created at CERN to review the research programme, the organizational structure, the industrial support and contracts, personnel and the accelerator sector divisional structure. Finally, an External Review Board has been created and will provide an Interim Report to Council in March 2002 with the Final Report available in June 2002.

      2. REPORT FROM THE ALICE REFEREES

      The Committee heard a report from the ALICE referees, concentrating on their reactions to the TDR for the Transition Radiation Detector (TRD). ALICE claims that the TRD, in conjunction with the Inner Tracking System (ITS) and the Time Projection Chamber (TPC), will provide electron identification in heavy-ion running in the central barrel region at momenta in excess of 1 GeV/c. In addition, the TRD could be used to trigger on high-pt (> 3 GeV/c) particles, thus providing not only enriched samples of g particles, but also the capability to select jets. Finally, the TRD could contribute significantly to the ALICE proton-proton physics programme, and in particular to charm and beauty physics, to the topological trigger function for the High Momentum Particle Identification Detector (HMPID) and to the measurement of jets.

      Following the Open Session presentation of the TDR in October, the LHCC referees had extensive discussions with ALICE to review the detector and the milestones. The LHCC considers that before a formal recommendation can be made, further discussions with ALICE on outstanding questions, such as the interpretation of test beam results, the effectiveness of linking tracks between the TRD and the TPC, the rejection power of the trigger and the exact detector configuration to be constructed given that currently only half of the costs are covered, is necessary. Following further questions and discussions with ALICE, the referees will make an additional report on the TRD TDR at the next meeting of the LHCC. The LHCC also asks ALICE to submit in advance the required documentation so that the cost evaluation of the detector can be performed in time for the final recommendation.

      The referees also provided updates to the status of the sub-systems and reviewed their milestones. The ALICE Collaboration has submitted reports to the LHCC documenting the status of key milestones. Good progress was reported on the HMPID, TPC, Trigger, and PHOS. The Addendum to the TOF TDR will be submitted in March 2002, while the date for the Addendum to the PMD TDR has not yet been agreed.

      Good technical progress was reported for the Dimuon Forward Spectrometer, but the cost estimate of the absorber has increased significantly since the Addendum to the TDR. The Collaboration is in the process of revising the design in order to reduce costs, while at the same time additional funds are being sought. As a result, the Production Readiness Review has been shifted from February 2002 to June 2002, thus reducing the contingency and putting the system on the critical path.

      H. Dijkstra, the consultant for the ALICE Inner Tracking System, reported on the status of the tracking system. Good progress was reported for the sensors and electronics of the Pixel Detector. Production of the electronics is expected to start in January 2002, which is a 6- month delay that the LHCC considers not critical. Efforts are continuing to reduce the layer thickness of the sensors. Following the demonstration of thin detector yield and assembly, production is scheduled to start at the end of 2002. Good progress was also reported on the Silicon Drift Detector. The detector is on schedule and the next milestone is that of May 2003 for the production of the first quarter of the module assemblies. Finally, the status of the Silicon Strip Detector was reviewed. Production of the radiation tolerant HAL25 electronics has been delayed from November 2001 to June 2002. This affects the rest of the project schedule, and in particular installation of the detector is delayed by 6 months to July 2005, leaving no contingency.

      3. REPORT FROM THE ATLAS REFEREES

      The Committee heard a report from the ATLAS referees, concentrating on developments since the last Comprehensive Review. ATLAS is in the process of finalizing their overall schedule and has submitted documentation summarizing the milestones. No major change to the schedule and milestones was reported compared to the status at the time of the July Comprehensive Review. Moreover, the referees reported on the outcome of the ATLAS RRB, at which support and encouragement for the ATLAS project was underlined. The RRB, although accepting their necessity, has not yet fully-approved the funds needed for the completion of the detector construction, and for the Maintenance and Operation (M&O) and Commissioning and Integration (C&I) costs. The CERN Management has requested ATLAS to make plans for several scenarios for the initial running of the experiment depending on the availability of the critical components and with the resulting physics performance.

      Good progress was reported on a number of sub-systems, including the Tile Calorimeter, Trigger/DAQ, Muon Spectrometer, Software, the Pixel Detector and SCT. However, the LHCC noted the problems with the TRT wire joints and the resulting impact of the schedule of the Barrel TRT. Tests on the glass tube joint of the Barrel TRT, which separates the wires of the straws in two halves, show that after an irradiation to a charge equivalent to about 1 month of high-luminosity operation, much of the glass has been etched-away resulting in HV-breakdown of the straw. Production of the wire joints and their stringing has been stopped. ATLAS is looking for replacement material for the wire joint and is also investigating an alternative gas mixture. The LHCC will continue monitoring the progress.

      4.  REPORT FROM THE CMS REFEREES

      The Committee heard a report from the CMS referees, concentrating on developments since the recent Comprehensive Review.

      The referees reviewed the CMS schedule and milestones. No major change to the schedule and milestones was reported compared to the status at the time of the October Comprehensive Review. Moreover, the referees reported on the outcome of the CMS RRB, at which support and encouragement for the CMS project was underlined. The RRB, although accepting their necessity, has not yet fully-approved the funds needed for the completion of the detector construction, and for the Maintenance and Operation (M&O) and Commissioning and Integration (C&I) costs. The CERN Management has requested CMS to make plans for several scenarios for the initial running of the experiment depending on the availability of the critical components and with the resulting physics performance.

      Owing to the delay in the underground area civil engineering, the critical path in the overall CMS schedule is the installation of the Trigger/DAQ from the surface to the underground areas. The planning of the critical path items will be investigated in further detail for the next meeting of the LHCC.

      The LHCC expressed its concern about the barrel RPC project. Although the contract has been signed with the manufacturing firm, a production schedule and Quality Assurance Plan is not yet available. Moreover, the production of gaps at the firm is not keeping up with the required rate. The LHCC will continue monitoring the progress of the barrel RPC project.

      The referees also reported on the CMS electronics. A recent CMS Electronics workshop was dedicated to discussing LV power supplies, grounding and shielding, optical links, as well as the status of the ECAL electronics. The LHCC had expressed its concerns during the CMS Comprehensive Review regarding the delays in the ECAL electronics. In the meantime, CMS has instigated a programme to evaluate how to proceed with the ECAL electronics. The LHCC considers that the issue remains critical, as it could result in significant delays to the ECAL project and cost overruns, and plans to continue monitoring the progress in forthcoming meetings.

      5.  REPORT FROM THE LHCb REFEREES

      The Committee heard a report from the LHCb referees, concentrating on the review of the Outer Tracker TDR, the status of several of the sub-systems and progress on re-optimizing the detector.

      The LHCb Collaboration is in the process of re-optimizing the detector by re-examining its material budget. The current number of nine tracking stations has resulted from dropping the station in the middle of the magnet and one just behind the RICH-2, as it was shown to not affect the tracking performance. While maintaining the technology and design of the individual tracking detectors, re-optimization of the remaining nine tracking stations is being studied in order to reduce further the amount of material in front of RICH-2. The re-optimization also includes reducing the material in the RICH-1 mirrors and the Vertex Locator RF shielding.

      As a result, submission of the Inner Detector TDR is now delayed by one year. The LHCC considers that the delay is not critical. Moreover, LHCb will submit an additional TDR showing the overall performance and integration of the tracking detectors.

      The referees also reported on their reactions to the TDR for the Outer Tracker detector. LHCb claims that the Outer Tracker, together with the more fine-grained Inner Tracker, will perform the charge particle tracking behind the vertex region with a system of nine tracking stations. The tracking system, consisting of the Inner Tracker and Outer Tracker, must perform the following tasks: find charge particle tracks in the region between the vertex detector and the calorimeters and measure the particle momenta, provide precise measurements of the direction of track segments in the two RICH detectors, and link measurements in the vertex detector with the calorimeters and the muon detector.

      6.  LHCb OUTER TRACKER TECHNICAL DESIGN REPORT

      The LHCC has completed its scientific and technical evaluation of the LHCb Outer Tracker TDR submitted in September 2001. The Committee was impressed by the quality of the work presented in the TDR and congratulates the Collaboration. The technology and design of the Outer Tracker are well-suited for reconstructing charged particle tracks, measuring their momenta, providing precise track segments for the RICH detectors, and linking measurements in the vertex locator with those in the calorimeter and muon system, and are adequate to achieve the physics goals stated in the LHCb Technical Proposal.

      The LHCb Collaboration is studying the possibility of reducing the material budget in the experiment and this study could affect the Outer Tracker. The Outer Tracker is part of an integrated tracking system that includes an Inner Tracker, which will be described in a future TDR. The LHCb Collaboration also intends to describe the integrated tracking system in a future TDR.

      The Committee has no major concerns. An ancillary document (LHCC 2001-041) contains items of lesser concern as well as a list of agreed milestones for monitoring the progress of the project. The LHCC review was not an engineering review, although some engineering aspects of the project were presented and discussed with the referees. The LHCC recommends that LHCb follows the established practice of conducting an independent review of the engineering design. Written reports should be made available to the LHCC through its referees.

      Recommendation:

      The LHCC recommends general approval of the LHCb Outer Tracker Technical Design Report, pending a final cost evaluation. The LHCC considers the schedule given in the TDR and the list of milestones in the ancillary document to be reasonable. They will be used by the Committee to measure and regulate the future progress of the project.

      7. REPORT FROM THE MOEDAL REFEREE

      The Committee heard a report from the MOEDAL referee, concentrating on developments since the last report to the LHCC. The MOEDAL Collaboration proposes to install a detector in the LHCb Vertex Locator region to identify the signature of monopoles through correlated signals in several plastic foils using etching techniques.

      The referee reported that MOEDAL is preparing a new experimental design, incorporating the approved lay-out in the LHCb Vertex Locator region. Furthermore, since the plastic foils should be capable of operating in the LHCb environment, several plastic foils have been irradiated in high-fluence beams of protons, neutrons and ions. Data from these tests are currently being analysed. In parallel, estimates of the radiation environment in the LHCb Vertex Locator area are in progress.

      The LHCC encourages the MOEDAL Collaboration to continue developing their experimental design with a view to submitting a Technical Proposal by March 2002.

      8.  TEST BEAMS

      M. Hauschild presented a status report on the SPS and PS Fixed Target Programmes. He reported on the water leak in a magnet of the PS East Hall, which resulted in the early stop to the T7 and T8 beam lines for 2001. He also reviewed the beam tests of ATLAS and CMS with the LHC-type bunch structure of 25 ns. spacing. Both the SPS and PS Fixed Target Programmes were completed for 2001 at the beginning of November.

      He also showed the machine schedules for 2002 as approved by the Research Board. The PS East Hall physics programme is scheduled to run from 6 May to 27 October, while the SPS from 27 May to 10 September with protons at 400 GeV/c2 and from
      25 September to 27 October with Pb-ions at 3 different energies (158 GeV/u, 20 GeV/u and 30 GeV/u). LHC-type beams with the 25 ns bunch spacing will not be available in 2002; they have been moved to the start of the SPS proton run in 2003.

      Moreover, he summarized the beam requests for 2002. Based on these requests, the 2002 fixed target programmes for the SPS and PS are being drawn-up.

      Finally, a detailed discussion on the use of test beams by the LHC experiments is scheduled for the January 2002 session of the Committee. Each of the LHC experiments is asked to present information on their use of test beams and to provide their long-term requirements.

      9.  INFRASTRUCTURE FOR LHC DATA CHALLENGES AT CERN

      J. Knobloch presented the infrastructure requirements for the planned LHC Data Challenges at CERN. Pending financing, the plan for 2002 consists of installing 400 dual processor systems for production, 44 TB disk space and tape drives with a sustained rate of 350 MB/s.

      10. REFEREES

      Following the changes to the LHCC membership, the new referee teams are as follows:

      ALICE: S. Bertolucci, J. Panman (Co-ordinator), P. Seyboth, C. Vallée

      ATLAS: A. Ceccucci, J.-J. Gomez-Cadenas, M. Jaffre, K. Tokushuku (Co-ordinator)

      CMS: J. Dainton (Co-ordinator), B. Löhr, J. Nash, H. Tiecke

      LHCb: D. Cassel (Co-ordinator), F. Ferroni, Y. Karyotakis

      MOEDAL: F. Ferroni

      TOTEM: J. Nash

      11. DATES FOR LHCC MEETINGS

    Dates for 2002:
    23-24 January
    13-14 March
    15-16 May
    3-4 July
    2-3 October
    27-28 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