CERN/LHCC 2004-024

                                                                                                                             LHCC 71
                                                                                                        4 August 2004


                                                                                                                                        

LARGE HADRON COLLIDER COMMITTEE

 

Minutes of the seventy-first meeting held on

Wednesday, 30 June and Thursday, 1 July 2004

 

OPEN SESSION:

1.     Production, Testing and Commissioning of the LHC Main Magnets: Lucio Rossi

2.     CMS Status Report: Tejinder Virdee

 

 

CLOSED SESSION:

Present:      W. Bartel, S. Bertolucci, K. Borras, M. Calvetti (Chairman), A. Ceccucci, J. Engelen, J. Feltesse, F. Ferroni, M. Hauschild, M. Jaffre, Y. Karyotakis, V. Kekelidze, J. Knobloch, M. Mangano, J. Martin, P. McBride, K. Potter, L. Robertson*, D. Schlatter, P. Seyboth, S. Smith, H. Tiecke,
E. Tsesmelis (Secretary), C. Vallee, T. Wyatt

                                                                                                            *) Part time

 

1.       PROCEDURE

The minutes of the seventieth LHCC meeting (LHCC 2004-016 / LHCC 70) were approved without modification.

The Chairman welcomed the new member S. Smith to the Committee.

2.       REPORT FROM THE CHIEF SCIENTIFIC OFFICER

The Chief Scientific Officer (CSO) reported on the status of the LHC Project. Following the delays in the installation of the LHC machine caused by difficulties in the QRL cryoline, the overall machine installation schedule remains under review. A revised LHC machine installation schedule will be released once the situation with the QRL cryoline has been fully evaluated. The aim is to be ready for the machine check-out and test with beam in the summer 2007. Delivery of the main dipole magnets continues.

3.    REPORT FROM THE ALICE REFEREES

The LHCC heard a report from the ALICE referees, concentrating on the general status of the detector construction, the status of the read-out electronics and on issues of integration.

Good progress was reported on the construction of the ALICE sub-detectors. Production of the ITS, the TPC, the TRD, the TOF, the HMPID, the PMD and the Dimuon Spectrometer are advancing well in their initial ramping-up phases. The Committee took note of the successful TPC sector test. Significant progress was reported on the TOF, Dimuon Spectrometer and TRD read-out electronics. The low-yield of the TOF HPTDC front-end electronics is under investigation with a new batch having been ordered from IBM. The TOF read-out electronics production schedule is not compromised by the extra time needed to resolve the low-yield issue. The LHCC requests ALICE to submit an overall production schedule for the read-out electronics components of all main sub-detectors.

Good progress was also reported on integration issues. Pre-commissioning on the surface is proving to be very useful but delays have already been incurred. Assembly of the front absorber is continuing. Work is advancing on the space frame TPC rails and modifications to the respective rails found to be necessary following trial insertions of the TRD and TPC are underway. The LHCC took note of incidents involving two different cranes at Point 2, resulting in a critical handling and space situation during the repair of the cranes.

The LHCC took note of the cost evaluation of the ALICE Trigger, Data Acquisition, High Level Trigger and Control System as reported in the submitted Technical Design Report. The Committee considers the assigned manpower and costs to be reasonable and they fit in to the overall envelope of the experiment.

4.    REPORT FROM THE CMS REFEREES

The LHCC heard a report from the CMS referees, concentrating on the general progress and the status of the Tracker, ECAL, HCAL, and Muon System projects and a report on the electronics, trigger and data acquisition systems.

The LHCC heard a report on the ECAL. The agreement between BTCP, ISTC and CERN for the interim period April to September 2004 is operational with all ovens working and delivery of crystals to CMS is in progress. A competitive tender for the remaining 23000 crystals for the Barrel ECAL and the required total of 15000 for the End-cap ECAL is in preparation at CERN. Initial radiation measurements on crystals from new suppliers are promising. Good progress was reported on the ECAL read-out electronics, as shown in the successful SPS beam tests with the LHC-type bunch structure, on the mechanics and on the cooling systems. The LHCC expressed its concern at there being no contingency left in the ECAL schedule and considers that the completion of the ECAL detector remains the biggest risk to the overall CMS schedule.

The referees also reported on the status of the Tracker. The LHCC noted the significant improvement to the quality of the thick sensors produced at ST Microelectronics. CMS will decide in July on the sharing of sensor production at ST Microelectronics and at Hamamatsu. The problem with the hybrid electronics via has been traced to poor Quality Control procedures at the manufacturing firm. The Quality Control will be improved but modules will go in to the Tracker with their long-term behaviour not completely certain. Due to this concern, the Committee asks CMS to present the criteria used for choosing the hybrids. The LHCC expressed its concern at there being no contingency left in the Tracker schedule.

Issues related to the assembly and qualification of the MINICRATE electronics, the production line for the MB4 chambers at Torino and the HV boards for the DTs are being resolved. The biggest risk for the DT schedule remains with the delivery of the HV boards.

The LHCC took note of the status of the CMS Computing. The referees reported that manpower issues are being addressed by the Collaboration and many lessons have been learned from Data Challenge 2004. A full report will be available at the end of August 2004.

The LHCC took note of the new CMS Master Schedule V34 and will use it henceforth to monitor the progress of the experiment. Production of the magnet coil is on schedule and although civil engineering is still subject to minor delays, installation of infrastructure in the underground areas has begun. Good progress was also reported on the Forward HCAL and the Computing.

The next LHCC Comprehensive Review of CMS will be held on 27-28 September 2004.

 

 

5.    REPORT FROM THE LHCb REFEREES

The LHCC heard a report from the LHCb referees, concentrating on the general status of the experiment and the schedule and milestones.

The LHCC took note of the good progress in the assembly of the dipole magnet and the installation of technical services and infrastructure at the LHCb experimental area as well as with the design of the experimental beam pipe. Due to problems encountered in the transport of the raw materials, construction of the muon spectrometer filter has been delayed by about one month. LHCb is studying ways to recover the time.

The referees also reported on the status of the sub-detectors. Good progress was reported on the VELO, the Trigger Tracker, the Inner Tracker, the Outer Tracker and the Calorimeters. The engineering run for the RICH HPD bump-bonding is advancing and the LHCC will continue monitoring its progress. Production of MWPCs for the Muon Spectrometer is underway at four sites, but delays have been encountered due particularly to problems with machined or pre-assembled parts being outside the specification. The estimated five-to-six-month delay makes it impossible to meet the original installation schedule. LHCb is working on a plan consisting of re-allocating production among the four sites, extending the installation well into 2006, and injecting additional resources. LHCb will present the detailed plan for both the production and installation of the MPWCs to the LHCC.

The Committee also heard a report on the Trigger and Computing. Improvements in the algorithms for the Level-1 and Higher-Level Triggers were reported and Data Challenge 2004 is underway with data having been produced and available.

The LHCC also took note of the LHCb milestones.

6.    TOTEM TECHNICAL DESIGN REPORT

The LHCC has completed its scientific, technical and cost evaluation of the TOTEM Technical Design Report (LHCC-2004-002 / TOTEM-TDR-001) submitted in January 2004 and the Addendum to the Technical Design Report (LHCC-2004-020 / TOTEM-TDR-001-Add. 1) submitted in June 2004. The Committee congratulates the TOTEM Collaboration for the work presented in the Technical Design Report and in the Addendum to the Technical Design Report.

The TOTEM experiment will measure the total pp cross-section and study elastic proton scattering. Two tracking telescopes, T1 and T2, installed on each side of the interaction point in a manner compatible with the CMS detector, will provide the acceptance required to measure inelastic pp collisions. The precise determination of the total cross-section requires TOTEM to also measure dsel/dt down to t ~10-3 GeV2. This will be accomplished with two sets of silicon detectors in Roman Pots located symmetrically on each side of the interaction point at 147 m and 220 m. Roman Pot stations at 180 m on each side of the interaction point might also be equipped later.

The LHCC finds the technologies adopted or proposed for the various components of the TOTEM experiment adequate to achieve the physics goals regarding the total cross-section and elastic proton scattering stated in the TOTEM Technical Proposal.

The Committee also noted that operating the TOTEM detector as a sub-detector of CMS raised the possibility to study hard diffraction. This will have to be evaluated further by the two Collaborations.

The Committee has no major concerns. An ancillary document (LHCC 2004-022 / G-078) 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 TOTEM follows the established process of conducting independent reviews of the engineering designs. Written reports should be made available to the LHCC through its referees.

Recommendation

The LHCC is convinced that the TOTEM experiment as described in the Technical Design Report and in the Addendum to the Technical Design Report can lead to a successful measurement of the total cross-section and of elastic proton scattering. Accordingly, the LHCC recommends approval of the TOTEM Technical Design Report. Recommendation for approval also pertains to all the physics which could be done with the proposed TOTEM detectors. The LHCC considers the schedule given in the Technical Design Report 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 LCG REFEREES

The LHCC heard a report from the LCG referees, concentrating on progress in ARDA, LCG-2 and a review of the computing resource requirements.

Good progress was reported on ARDA Architectural Roadmap to Distributed Analysis - a project of the LCG whose main activity is to enable LHC analysis on the Grid. ARDA is up and running and development of the associated initial gLite middleware prototype is advancing. Issues to be addressed prior to the LCG Comprehensive Review in November 2004 are requirements of a distributed analysis system based on EGEE (Enabling Grids for E-science in Europe) middleware and those for gLite together with a clearer definition of the gLite connection to the experiments.

The LHCC took note of the progress in the planning of the data management for LCG-2. Development of the LCG-2 service is continuing in an effort to deploy and validate the basic underlying infrastructure.

The Committee also discussed the future review of the computing resource requirements disks, tapes, CPUs and networks for Tier 0, Tier 1 and Tier 2 - of the experiments. The LCG Project Overview Board (POB) has requested an LHCC review of the updated estimates and the Committee will organize such a review in the autumn 2004.

The next LHCC Comprehensive Review of the LCG Project is scheduled for 22-23 November 2004.

8.    TEST BEAMS

The SPS and PS Physics Coordinator gave a report on the status of CERNs accelerator complex and on the LHC test beams.

He reported on the problems in the PS Complex and in the SPS. Water leaks in the PS Booster and in the PS extraction septum have caused delays in the fixed target programmes for the LHC experiments. Additional delays were reported due to an SPS vacuum leak in the North Area. Following repairs to these systems, the accelerator complex has again been operational. The Coordinator also outlined plans for a long-term consolidation programme of CERNs accelerator complex.

The Coordinator also reported on the successful scrubbing and LHC-type bunched beam runs at the SPS. The good beam availability and stability allowed the respective experiments to take good quality data.

He also reported on a possible extension to the SPS run in to November 2004. In order to compensate for the delays at the beginning of the 2004 SPS run, it is proposed to extend the run by an equivalent time. A decision will be taken in the coming weeks.

The LHCC will discuss the plan for test beams in 2006 at its September 2004 meeting.

 

9.    ATLAS COMPREHENSIVE REVIEW

The fifth of the LHCC Comprehensive Reviews of ATLAS took place on 28-29 June 2004. The LHCC referees addressed the following areas: Inner Detector, LAr Calorimeters, Tile Calorimeter, Muon Spectrometer, Combined Test Beam and Electronics, Planning for ATLAS Commissioning, Trigger/DAQ, Computing and Software, Physics Studies and the topics of Management, Technical Coordination, Installation, Schedules and Costs.

Since the previous ATLAS Comprehensive Review in July 2003, the ATLAS Collaboration has made very significant progress towards the realisation of an experimental set-up ready to record proton-proton collisions at the LHC in 2007. In particular, construction of the majority of the final components is either well-underway or completed, installation of the technical infrastructure in the underground caverns is well-advanced, installation of the first sub-detector elements of the ATLAS experiment in the underground cavern has been successful, and preparations for the commissioning of the ATLAS experiment are in progress. The procurement of the front-end electronics has in general been successfully completed.

It is realistic to expect ATLAS to have an initial working detector for the start of LHC operation in 2007, although detector installation can be foreseen beyond this date. However, the LHCC considers that the ATLAS plan to have commissioned an initial working detector by the end of 2006 is challenging, as a number of systems no longer have any contingency in the schedule, originally included as a safety margin for their installation. The schedules of the the Barrel Toroid Magnets, the End-cap Toroid Magnets, the Barrel and End-cap SCT, and the TRT End-cap A are considered to be critical. The LHCC observes that additional resources, both in terms of money and manpower, would aid in completing the initial detector.

Detector elements not installed by the LHC start-up in 2007 will be staged. The staging plan consists of deferring installation of some components of the Inner Detector, the Calorimetry, the Muon Instrumentation, the Higher-level Trigger, DAQ and the radiation shielding. Their installation in a long shutdown, while requiring additional resources, would complete the ATLAS detector as described in the approved Technical Design Reports.

The conclusions and concerns of the LHCC are given below. They will allow the Committee to follow-up outstanding issues and to monitor future progress of this project in upcoming sessions of the LHCC prior to the next ATLAS Comprehensive Review.

      Construction of the Inner Detector is advancing well and several outstanding problems have been solved since the previous Comprehensive Review. No major concerns were reported for the Pixel detector, but critical items have been identified for the Transition Radiation Tracker (TRT) End-cap A and the Barrel and End-cap Semiconductor Tracker (SCT). Delays have resulted in these systems having used up the contingency in their installation schedule.

      Production of all LAr Calorimeter modules and assembly of the wheels is complete. Integration activities and cool-down of the cryostats are advancing well. The major outstanding problem area is related to the timely delivery of the negative voltage regulators.

      Construction of the Tile Calorimeter is very advanced and the first modules have been installed successfully in the ATLAS underground experimental area. Plans for the detector general services, testing, and commissioning are considered to be reasonable.

      Good progress was reported on the Monitored Drift Tube (MDT), Cathode Strip Chamber (CSC), Resistive Plate Chamber (RPC) and Thin-Gap Chamber (TGC) detectors and a significant number of chambers, together with their front-end electronics, have been produced. The major outstanding concern remains the timely delivery of the Big-Wheel chamber support structures.

      The LHCC took note of the successful on-going ATLAS Combined Test Beam and considers it to be an essential component of the ATLAS pre-commissioning stage. Good progress was reported on the ATLAS electronics with most of the systems having been produced. Fabrication of the Pixel FEI, the RPC CMA and the TGC SLB front-end chips is on the critical path.

      The LHCC took note of the plan for commissioning the ATLAS experiment and considers it to be reasonable and to be handled in a thorough and professional manner.

      No major concerns were expressed for the Calorimeter Trigger, the Higher-Level Trigger and the DAQ. The schedule to complete the Muon Trigger is tight and the LHCC will continue monitoring progress.

      Significant progress was reported on the Software and Computing. Software releases for Data Challenge 2004 and for the Combined Test Beam have been delayed slightly, but much of the planned functionality has been made available. The planning for Data Challenge 2004 and for the Combined Test Beam is reasonable. The ATLAS Database Project has been created and is operational.

      The ATLAS physics studies are currently concentrated on the continuing evaluation of the physics potential and detector performance. At a future meeting, the LHCC will review the ATLAS organization that will coordinate the physics studies with LHC data, particularly during the initial data-taking phase.

      Significant progress was reported on the construction of ATLAS detector since the previous Comprehensive Review. Although the schedule for the installation of several sub-systems the Barrel Toroid Magnets, the End-cap Toroid Magnets, the Barrel and End-cap SCT, and the TRT End-cap A - remain critical, the Committee considers that it is realistic to expect ATLAS to install an initial working detector for the start of LHC operation in 2007. Should the total Cost-to-Completion not be covered, detector elements not installed by the start-up of the LHC in 2007 will be staged. The LHCC congratulates the ATLAS Collaboration for the significant progress since the previous Comprehensive Review.

 

10.     DATES FOR LHCC MEETINGS

          Dates for 2004:

29-30 September

24-25 November

 

The LHCC received the following documents:

         Cost evaluation: TOTEM Technical Design Report (LHCC 2004-013/G73)*

         Cost evaluation: ALICE Trigger DAQ system TDR (LHCC 2004-014/G74)*

         TOTEM Technical Design Report Addendum (LHCC 2004-020/TDR 1/Add. 1)

         CMS Milestones (LHCC 2004-021/G77)*

         ATLAS Comprehensive Review (LHCC 2004-023/LHCC G-079)*

 

* restricted circulation

 

                                                                Emmanuel Tsesmelis

                                                                Email:    LHCC.Secretary@CERN.CH

                                                                Tel. 78949, 164057

 

LHCC Secretariat:    Janet Grant (Bldg. 14/4-022) Tel. 73424

                                 janet.grant@CERN.CH