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CERN/LHCC 2005-020
LHCC76
30 May 2005
LARGE HADRON COLLIDER COMMITTEE
Minutes of the seventy-sixth meeting held on
Wednesday, 11 May 2005
OPEN SESSION:
1. CMS Status Report: T. Virdee
2. Report from the 3rd Meeting of the TeV4LHC Workshop: M. Mangano
CLOSED SESSION:
Present: S. Bertolucci (Chairman), K. Borras, P. Dauncey, J. Engelen, F. Forti, J. Haba, M. Hauschild, S. de Jong, V. Kekelidze, J. Knobloch, R. Landua, M. Mangano, J. Martin, M. Martinez-Perez, P. McBride, B. Peyaud, K. Potter, D. Schlatter, E. Tsesmelis (Secretary)
Apologies: C. Niebuhr, S. Smith, C. Vallée
1.PROCEDURE
The Chairman welcomed the new member R. Landua to the Committee.
The minutes of the seventy-fifth LHCC meeting (LHCC 2005-009 / LHCC 75) and the report from the ALICE Comprehensive Review (LHCC 2005-010 / G-093) were approved without modification.
2.REPORT FROM THE CHIEF SCIENTIFIC OFFICER
The Chief Scientific Officer (CSO) reported on the LHC Project. He underlined that significant efforts are being made to complete installation of the LHC machine on time, including requests for additional resources, in order to be ready for first proton collisions in the summer of 2007. The LHC experiments have been asked to quantify their extra needs for installation and commissioning to meet the above milestone of LHC start-up. The LCG financial plan for Phase II, covering the period 2006-2008, is being prepared. All elements of the LHC Project – machine, experiments, and LCG – are being put into CERN’s Medium Term Plan to be presented to Council in June 2005.
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 installation tests and a presentation of the overall milestones.
The Committee heard a report on the ALICE milestones. Most of the critical milestones have been met. A concern lies with the production of the MANAS read-out chip for the Muon System and Photon Multiplicity Detector (PMD). The latest version of the MANAS chips, currently being tested in a Singapore firm, still exhibit a larger than expected gain dispersion. Since measurements of the gain dispersion at other sites are within specification, the measurement system at the Singapore firm is put into question. A visit to the Singapore firm is planned by ALICE and the LHCC will continue monitoring the production and quality of the MANAS chips.
Good progress was reported on the V0 Detector. Construction of Sector#0 for V0A (V0A-0) is complete. V0A-0 has been tested with cosmic rays and radioactive sources and the construction protocol is being produced ahead of the Production Readiness Review for the series production. To complete the design of the support tube and protection box, information from the ALICE integration group is urgently needed. Production of V0C Sector#0 (V0C-0) will be complete only in June 2005 owing to the late delivery of the scintillators. Series production of the V0C is scheduled to start in September 2005 and the full V0C array will be delivered in December 2005 as expected.
The referees also reported on the status of the Inner Tracking System (ITS). No major concerns were raised for the Silicon Pixel Detector (SPD) and most of the components are ready. Production of the first sector is in progress but the LHCC noted that the sector integration to the SPD Half Barrel (HB) has not yet started. The unexpected I-V behaviour observed in some sites, which has stopped the module Silicon Strip Detector (SSD) assembly, has been understood to come from a poor alignment of pads causing a short to the bulk material, and has been rectified. However, no SSD ladders have been assembled and the procedure has not yet been proven. The Committee took note that the very low yield for the sensor production for the Silicon Drift Detector (SDD) at the firm Canberra has been identified and solved. But the start of module assembly has been delayed by 10 weeks due to modifications to the microcable. The Committee considers that the planned start of ladder assembly in July 2005 will be difficult to meet. The LHCC considers that the on-time completion of the ITS remains the ALICE premier concern. A realistic revision of the ITS schedule is necessary in October 2005, once all types of assembly procedures are commissioned. Every effort should be devoted to establishing these procedures as soon as possible.
The LHCC heard a report on the test installation of several sub-systems and on the Space Frame load tests. The delicate and complex integration test of the Time Projection Chamber (TPC)/ITS/Beampipe/V0/F0/Forward Multiplicity Detector (FMD) is complete and proved to be very successful. The overall installation scenario was certified and works well. The TPC load test of the Space Frame was also successful and provided results in good agreement with expectations. The upcoming TOF/TRD tests in June 2005 are in preparation.
The Cost Evaluation of the ALICE Forward Detectors (LHCC 2005-011 / G-092) was submitted to the LHCC. The cost estimates are based on quotes from industry and prototype work and include spare parts. The costing of the V0, T0 and FMD Forward Detectors is considered to be reasonable and fits into the overall cost of the ALICE experiment. The ALICE Collaboration is, however, urged to provide a manpower assessment for the T0 and V0 projects. No extra cost is expected to arise for assembly space, storage space or safety installations.
4. REPORT FROM THE ATLAS REFEREES
The LHCC heard a report from the ATLAS referees, concentrating on the general progress, and the status of the electronics, Inner Detector and Muon Spectrometer.
Good progress was reported on the Barrel Toroid (BT). The last coil will be ready for installation by the end of June 2005. The committee reviewing the non-conformity in the ground insulation of the BT-3 coil concurred with the ATLAS proposal not to attempt to repair the coil and to install it in a position that minimizes the worst-case voltage to ground. Moreover, the review recommended that a second cold test be carried out on the surface in order to verify that the condition of the coil has not worsened.
The referees also reported on construction of the Big Wheels for the Muon Spectrometer. All material for the Monitored Drift Tubes (MDTs) and the Thin Gap Chambers-1 (TGCs-1) will be at CERN by November 2005, all the tooling will be at CERN by the end of May 2005, all the necessary space has been made available in Building 180, and the development for TGC-2 and TGC-3 is in progress. Given the tight schedule, the LHCC will continue monitoring progress of the Big Wheel construction.
Good progress was also reported on the installation at Point 1. Installation of services for the Barrel Calorimeters is in progress, muon chambers are being mounted in the BT structures, installation of the DAQ has commenced, and the four major cabling campaigns are starting in May 2005. Commissioning of the LAr Calorimeter, Tile Calorimeter and Muon Chambers has also started. The LHCC took note that ATLAS is preparing an action list to be submitted to the LHCC referees in response to the report from the recent Installation Review.
The Committee heard a report on the status of the ATLAS electronics. All ASIC electronics are now available. Progress was reported on the front-end and back-end systems, as well as on the power supplies. However, the LHCC took note of the delays in the LAr Calorimeter Front-end Board (FEB) production, which could have an impact on the calorimeter’s schedule, of the LAr Calorimeter LV power supplies and on the Pixel LV/HV power supplies.
The referees also reported on the status of the Inner Detector. Production of the Pixel module and final tests are progressing well and production of the Pixel disks is proceeding smoothly and within schedule. However, the LHCC noted the following concerns: the two-month delay in the milestone for being ready for loading on supports, the temporary slow-down in the module production due to a failure observed after several thermal cycles, and the problem associated with the first batch of staves showing a problem of delamination. The latter problem is particularly serious and the LHCC will monitor developments closely. Production of the Barrel and Enc-cap Semiconductor Tracker (SCT) is advancing but a large number of cracks have been observed on the LMT connections. The problem is related to the fragility of the Al/kapton and a recovery plan is being implemented by ATLAS with the aim of meeting the SCT installation milestone. The LHCC noted the loss rate of fuses for the Transition Radiation Tracker (TRT). The fuses are required to protect the detector from destructive discharges but a significant number fail at either the production or quality control stages. ATLAS is evaluating the problem and will provide a report on the adopted solution to a future meeting of the LHCC.
Production of Muon Chambers is progressing according to schedule and is approaching completion. The one outstanding concern lies with the tight schedule for integration and tests of the Resistive Plate Chambers (RPCs).
5. REPORT FROM THE CMS REFEREES
The LHCC heard a report from the CMS referees, concentrating on the status of the Tracker, Muon System, Computing, Physics and TriDAS (CPT), and the schedule of the experiment.
The LHCC heard a report on the Tracker. The referees were very impressed by the progress in the last few months. Production of modules and hybrid electronics is well under way and the quality is deemed to be excellent. Following approval by the Tracker Management Board, preparations for the Tracker sub-detector integration have started. A Tracker Integration Team is to be put together at CERN and significant improvements are being made to the Tracker Integration Facilities at CERN, developments that the LHCC considers imperative in order for the Tracker to meet the ready-for-installation milestone of 1 November 2006. The draft Tracker schedule remains very aggressive as time is very short. Contingency must still be generated in the schedule and production of modules must continue to be optimised. Integration of the Tracker End Cap (TEC) must accelerate to be complete in May 2006 and detailed plans for the Tracker integration and commissioning are crucial to meet the schedule. A number of new groups have recently joined the CMS Pixel Project and discussions for incorporating the Pixel Project into the Tracker Project have started.
The referees also reported on the Muon System. Production of Drift Tube (DT) chambers at the four production sites is advancing well. Installation of DTs into the CMS yoke structures is currently limited by the availability of MINICRATE electronics units. The MINICRATE production rate needs to ramp-up. Problems with some MINICRATE boards once connected to chambers have been understood and rectified. Production of Barrel and End-cap Resistive Plate Chamber (RPC) detectors is progressing well while the installation and commissioning of Cathode Strip Chambers (CSCs) in CMS is well-advanced.
The LHCC took note of issues concerning the CPT. Preparation of the two-volume Physics Technical Design Report has started. Volume I, covering detector performance and operations, physics reconstruction tools and software and data issues, will be submitted to the LHCC in December 2005 and Volume II, presenting the plan for the full analysis of data from the first physics run to the nominal luminosity runs, will follow in April 2006. The LHCC requests submission of a more detailed CPT milestone list and to this end a set of milestones up to 2007 will be presented to the June 2005 Comprehensive Review.
The referees also reported on progress regarding other issues. Good progress was reported on the civil engineering, the installation of infrastructure, magnet, the forward radiation shielding, and the Hadron Calorimeter. New contracts are being prepared with the SIC and BTCP entities for the remaining production of the ECAL crystals. The LHCC noted that the on- and off-detector cabling is now on the critical path and the Committee will monitor progress closely in this field.
The Committee also heard a report on the overall CMS schedule. The CMS Master Schedule V34.2 became the baseline on 1 May 2005, and the sub-detectors are now re-baselining their individual schedules and milestones to the new Master Schedule. The LHCC will review the CMS schedule in further detail during the June 2005 Comprehensive Review.
6. REPORT FROM THE LHCb REFEREES
The LHCC heard a report from the LHCb referees, concentrating on the status of the detector construction and on the Second Addendum to the Muon System Technical Design Report.
The referees reported on the Tracker. Progress was reported on the Vertex Locator (VELO). The two-sided bonding has been tried out successfully. A delay of 3 months in the VELO was reported mainly due to the non-flatness of the last batch of prototype hybrid electronics. The required production rate of modules needs to be demonstrated and the module production schedule remains tight. Good progress was reported on the ancillary systems, including the vacuum system, bellows, RF box, prototype CO2 cooling system and the Al-cast capillaries. Production of sensors and ladders for the Trigger Tracker (TT) is now advancing well. Problems with the via connections of the TT and Inner Tracker (IT) have been solved but delivery of the pre-series printed circuit boards is now on the critical path. Delays in the production of the Outer Tracker (OT) have been recovered and a beam test of an OT set-up at DESY was successful. A medium scale test is currently under preparation and will probe the engineering of the detector as a whole.
The Committee heard a report on the RICH detectors. The last of the Hybrid Pixel Detector (HPD) read-out units will arrive only in January/February 2007, but their installation in the RICH detectors is considered to be clear-cut. The Committee took note that the RICH-1 installation schedule has been aligned to the LHC Injection Test schedule. Installation of the flat mirrors in the RICH-2 has been delayed by one month due to the first batch not being within specification.
Good progress was reported on the calorimeter system – ECAL, HCAL, Scintillator Pad Detector (SPD) and the PreShower Detector (PS) - with no major concerns having been identified.
The Muon System is equipped with MWPCs, with the exception of the innermost region of the first station M1. MWPC detectors for the Muon System are in production at all sites. More than 400 chambers have been built and the 393 tested are of good quality. The Committee, however, took note of the outstanding delay in MWPC production, which indicates that the M2-M5 chambers will be in time while the M1 chambers will be arranged to optimize the physics output. Following studies comparing the performance of asymmetric MWPCs and GEMs in a high rate environment, the LHCb Collaboration proposes to use triple-GEM detectors in the innermost region of the M1 station as described in the submitted Second Addendum to the Muon System Technical Design Report. The LHCC is currently reviewing the Second Addendum and will provide its recommendation at an upcoming meeting of the Committee.
The referees also reported on the Trigger and Computing. Progress with the Computing Data Challenge Phase II has been slow due to difficulties encountered in the data production and stripping. LHCb manpower is now needed for the Real Time Trigger Challenge that is planned for June-July 2005. Optimisation of the manpower plan for the two Challenges is under way. Preparation for Phase III of the Computing Data Challenge is in progress.
LHCb is aligning the individual system and experiment installation schedules to be in the line with the recently released LHC Installation Schedule, dated 1 April 2005, and will submit it to the next LHCC session. No major changes are expected to the LHCb schedule presented at the April Installation Review. LHCb is continuing to monitor developments in the installation of the LHC machine cryogenics at Point 8, for which any further delay will interfere with the LHCb installation work.
7. REPORT FROM THE TOTEM REFEREE
The LHCC heard a report from the TOTEM referee. The recent meeting between TOTEM and CMS was considered to be successful by both parties and the Letter of Intent for common TOTEM / CMS physics is expected to be submitted to the LHCC in November 2005. Contacts with the LHC machine groups is on-going, particularly in view of the work towards the development of a prototype for which the vertical and horizontal Roman Pots are mounted as close as possible and for which the Beam Position Monitor is fixed to the same mechanical structure as the Roman Pots. Measurements to study RF coupling are continuing. The Committee noted that CERN has made available construction funds for TOTEM for 2005 and preparation of the TOTEM Memorandum of Understanding is in progress. A more detailed presentation will be given at the next meeting of the LHCC.