CERN/LHCC LHCC March 2007 LARGE HADRON COLLIDER COMMITTEE

Transcription

1 LARGE HADRON COLLIDER COMMITTEE Minutes of the eighty-seventh meeting held on Wednesday and Thursday, March 2007 CERN/LHCC LHCC March 2007 OPEN SESSION: 1. LHC Status Report: Emmanuel Tsesmelis 2. Early TOTEM Running with the 90 m. Optics: Karsten Eggert 3. MOEDAL Status Report: James Pinfold CLOSED SESSION: Present: S. Bertolucci (Chairman), J.-J. Blaising, P. Dauncey, S. de Jong, J. Engelen, M. Ferro-Luzzi, F. Forti*, M. Gonin, J. Knobloch, M. Mangano, R. Mankel, M. Martinez-Perez, P. Mato, C. Niebuhr, B. Peyaud, C. Rembser*, S. Smith, E. Tsesmelis (Secretary), R. Yoshida Apologies: S. Dalla Torre, J. Haba, V. Kekelidze * part-time 1. PROCEDURE The minutes of the eighty-sixth LHCC meeting (LHCC / LHCC 86) and the report from the LHCb Comprehensive Review (LHCC / LHCC-G-126) were approved. 2. REPORT FROM THE CHIEF SCIENTIFIC OFFICER The Chief Scientific Officer (CSO) reported on the status of the LHC machine installation and commissioning. Installation of the LHC machine is proceeding well and the project is advancing towards meeting its milestone for closure at the end of August 2007, albeit on a tight schedule. Cool-down of Sector 7-8 is well-underway. The engineering run at 450 GeV beam energy for the end of 2007 remains the top priority. Communication channels between the LHC machine and experiments is considered to be very important and to this end the LHC Installation and Commissioning Committee (ICC) and the LHC Experiment Machine Interface Committee (LEMIC) are two forums to exchange information between the LHC machine and experiments. Discussions on the White Paper are continuing and more information is expected in time for the Council Week of June REPORT FROM THE ATLAS REFEREES The LHCC heard a report from the ATLAS referees, concentrating on the status of installation and of the Inner Detector, and on the review of the power supplies and the online and offline data quality monitoring. The Committee heard a report on the status of the ATLAS installation. Installation of the Barrel Muon chambers is nearing completion and the End-cap Muon chamber installation is now progressing on both sides. The first End-Cap Toroid (ECT) has been transported from Hall 191 to the external test station in front of Building 180 where it is being cold-tested mechanically at LN temperatures following a smooth

2 2 cool-down phase. The integration of the second ECT is advancing well with the cold mass having been inserted into the vacuum vessel. The referees reported on the status of the Inner Detector. The Barrel Transition Radiation Tracker (TRT) and Semiconductor Tracker (SCT) are installed while the End-Cap TRT and SCT are now ready for installation after being integrated and tested. The Pixel detector together with the beryllium experimental beam pipe will be ready for installation in May The critical issue is with the failure of the heaters of the SCT evaporative cooling system. Ingress of moisture in the power unions and then in the MgO powder that insulates the heating wire from the inox sheath caused a short to ground destroying the power union. Analysis of the failure is in progress and repair plans, together with the impact on the ATLAS schedule, are being developed. The LHCC heard a report on the ATLAS power supplies. Progress was reported on the resolution of outstanding issues. The repair of the low voltage supplies for the Tile Calorimeter is now well-defined and production of the retro-fitted units is now underway. The schedule to complete the low voltage power supplies for the LAr Calorimeter remains critical. A new strategy is being implemented to solve the difficulties and consists of awarding a new contract imminently and developing a back-up plan based on two options. The delivery schedule for the Muon System power supplies still does not satisfy the requirements and at the current rate only a partial power supply configuration will be available for Previous concerns regarding the power supplies for the Inner Detector and LAr Calorimeters have been resolved successfully. The referees also reported on the ATLAS data quality assessment and monitoring (DQ). The infrastructure for these tasks is being put in place and ATLAS is initially using Monte Carlo samples to develop the appropriate tools. The LHCC acknowledges the global approach to DQ taken by ATLAS. Much remains to be done but it is expected that the most critical pieces will be available by summer REPORT FROM THE CMS REFEREES The LHCC heard a report from the CMS referees, concentrating on the status of the CMS sub-detectors and on the review of the High Level Trigger. The referees reported on the status of the CMS sub-detectors. The Tracker has been completely tested and integrated into the Tracker Support Tube. Running with cosmicrays at the Tracker Integration Facility (TIF) has been highly successful and about 400,000 cosmic-ray triggers are being reconstructed for analysis. The simultaneous alignment of all pixel and strip modules has started to be performed with Millipede II. Good progress was reported on the Electromagnetic Calorimeter (ECAL). All crystals for the Barrel ECAL (EB) have been received and all Supermodules will be completed by mid-april Crystal production for the End-Cap ECAL (EE) has started at both producers. Agreement with BCTP for the final crystals for the EE has been reached and delivery of the crystals is expected to be finished by the end of February Integration of the ECAL is also advancing well. Production of the new motherboards is well-underway and the already-produced units are of excellent quality. Fourteen Supermodules with the new motherboards are ready for integration. Construction of the first EE Dee from the series production has started. Lowering of the CMS detector elements to the UXC55 experimental cavern is advancing well. The first phase of this lowering campaign has been completed on schedule, and includes the YB0 central barrel yoke with the superconducting coil. Reviews for the YB0 services have been held and work has started. The piping design has been greatly simplified and the resource-loaded schedule indicates that sufficient manpower is available to complete the services on time. However, it is imperative for CMS to continue monitoring all supply-line schedules, such as those for the Muon System cables.

3 3 The referees reported on the status of the High Level Trigger (HLT). Activity in this area has increased markedly. The group has been strengthened. New algorithms and trigger paths that can run in the actual HLT conditions have been developed. The LHCC considers that in order to make further progress, more attention is needed in the organization of tasks taking into account a more global strategy, especially in composing a good trigger menu, finalising porting of the code to the new software framework and developing a list of objectives and metrics to set priorities. Plans for the Computing, Software and Analysis 2007 (CSA07) Challenge are being prepared. The referees reported on the CMS schedule. Progress since the previous meeting of the LHCC in January 2007 has been outstanding and as a result CMS was able to hold the schedule since then. CMS has developed a contingency plan to identify critical path tasks which could be curtailed and postponed to the shutdown period. The schedule to complete the initial CMS detector for the LHC run later in 2007 remains very tight but credible. 5. REPORT FROM THE LHCb REFEREES The LHCC heard a report from the LHCb referees, concentrating on the LHCb detector construction, installation and commissioning. Good progress was reported on the construction, installation and commissioning of the LHCb sub-detectors. Production of the Vertex Locators (VELO) modules, Inner Tracker (IT) and Trigger Tracker (TT) ladders, Hybrid Pixel Detectors (HPDs) for the Ring Image CHerenkov (RICH) detectors and chambers for the Muon System are either complete or approaching completion. Installation of the detector infrastructure and services, such as the long-distance cabling is essentially complete. Installation of sub-detectors is progressing well. The installation of the VELO, RICH-1 and Muon System detectors is proceeding well, the mechanical C-frame supports for the Outer Tracker are nearly all in place and the installation of the experimental beam pipe is well-advanced. Commissioning of the LHCb experiment has also started with work on the L0 Trigger and Calorimeter. Commissioning of the RICH-2 and the Online System will follow soon. The large number of tasks being undertaken in the UX85 LHCb experiment cavern is made possible through the excellent co-ordination structure put in place for work in the tight space available. The studies on understanding and mitigating the ageing effects observed in the Outer Tracker modules from the mass production are continuing, but the source of the problem to ensure its long-term solution remains outstanding The LHCC is confident that LHCb will be able to exploit usefully the first collisions during the LHC engineering run at the end of REPORT FROM THE LCG REFEREES The LHCC heard a report on the LCG, concentrating on the requirements from the experiments and the status of data storage elements. The referees reported on the LCG requirements by the experiments. Commissioning of the LCG for the experiments is advancing well. Some delays have been noted in the deployment of the World-wide LCG (WLCG), most notably in the area of Storage Resource Manager SRMv2.2. The experiments have also developed re-scaled computing models, adapting to the projected LHC luminosity with time. In particular, ATLAS, CMS and LHCb have pledged resources that are essentially in line with their requirements. However, care must be taken to ensure that the resources that actually become available are indeed what have been requested. The pledged resources for ALICE at present are less than what are required and discussions are underway to address this deficit. A so-called Megatable, which provides the inter-relationship and bandwidth between Tier centres is evolving. The transfer rate between Tier centres is improving but it still needs to be stabilised. The LHCC also heard a report on the status of the data storage elements. The Committee noted a considerable improvement in this area since the beginning of this year, but more work is needed to fully complete their deployment at the LHC. It presently remains unclear whether the Dress Rehearsal scheduled for July 2007 will be

4 4 able to use SRMv2.2 on either the dcache or CASTOR storage management services. The most critical issues concerning CASTOR have been addressed successfully and now the service needs to be deployed and tested in a production environment. 7. REPORT FROM THE MOEDAL REFEREE The Committee heard a report from the MOEDAL referee, concentrating on developments towards the final design of the MOEDAL experiment and towards the MOEDAL Technical Proposal. The design of the MOEDAL experimental set-up has evolved from the configuration in 2006 and contacts have been strengthened further with the LHCb Vertex Locator (VELO) group concerning integration of the MOEDAL detector around the VELO. The new MOEDAL set-up consists of deploying detectors on the walls and ceilings of the VELO cavern. This solution has the advantage of removing concerns regarding the heat build-up on the VELO, the lengthy access to the VELO detector and electronics and the suspension of the MOEDAL detector over the VELO but at the expense of a reduced MOEDAL acceptance. The LHCC encourages the MOEDAL Collaboration to continue with the design of their experimental set-up with a view of submitting the Technical Proposal by the end of 2007, one year later than originally planned. 8. TEST BEAMS The SPS and PS Coordinator gave an overview of the users schedule at the PS and SPS for 2007 and reported on the future of the Gamma Irradiation Facility (GIF). The Co-ordinator reported on the PS and SPS fixed target programes. The PS and SPS fixed target programmes have been submitted to the users. Some beam time remains available for new requests at both facilities. The Co-ordinator reported that the repair of the septum magnet MNP23 at the PS East Hall will not be possible for the 2007 run and a solution based on using a dipole magnet will be introduced. The implication of this is that a new operation scheme will be used at the East Hall whereby the beam will be shared between three users T7, T9-T10 and T8. Although less beam will be available per day, given daily scheduling it will nevertheless be possible to fulfill all needs of the users. The Co-ordinator also reported on the GIF. The facility will continue to run in 2007 and in 2008 with several users in its current configuration and with support from CERN being guaranteed. An upgraded facility beyond 2008 is being discussed and a small working group, which includes representatives from the LHC experiments, is considering various options. 9. ALICE COMPREHENSIVE REVIEW The seventh of the LHCC Comprehensive Reviews of ALICE took place on March The LHCC referees addressed the following systems and areas: Inner Tracking System and Time Projection Chamber, Particle Identification and Dimuon Spectrometer, Forward Detectors and Calorimeters, Trigger, High-Level Trigger, DAQ, Controls and Offline, Installation and Commissioning, Strategy for Data-taking, Alignment and Calibration, First Physics, and the topics of Management, Technical Coordination, Integration, Schedules and Costs. Since the sixth of the Comprehensive Reviews in March 2006, the ALICE Collaboration has made very significant progress towards the realisation of an experimental set-up ready to record proton-proton and heavy-ion collisions at the LHC. The LHCC considers it reasonable to expect ALICE to be ready with an initial working detector for the start of LHC operation in 2007, assuming that the timely delivery of sub-detectors and the smooth advancement of the production schedules remain ensured, and detector installation can be foreseen beyond this date. Construction of final components for the initial detector configuration is approaching completion. Installation and commissioning of the ALICE detector and sub-systems is advancing well and reasonable plans are put in place for the data-taking, alignment and

5 5 calibration as well as for the initial physics programme. The LHCC noted as a concern the late installation and the resulting tight schedule in the installation of the Miniframe, which carries services without which commissioning of the sub-detectors cannot be completed, and in the delivery of the power supplies required for the ALICE commissioning. Compared to the schedule at the Comprehensive Review last year, the current status is five months later than planned but the delay of the LHC schedule by four months has meant the rest of the installation is still feasible, although it remains very tight. 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 ALICE Comprehensive Review. Excellent progress has been reported on the Inner Tracking System (ITS). The Silicon Drift Detector (SDD) and Silicon Strip Detector (SSD) are integrated in the ITS and the Silicon Pad Detector (SPD) integration is to follow soon. The late connection of services means that the final testing of the ITS can only be done very late, leaving no possibility of repair for any serious problem that might be found. The Time Projection Chamber (TPC) installation and commissioning is under control. The chambers are in excellent condition as shown by test results using various methods. All particle identification detectors of ALICE have made very good progress since the last Comprehensive Review. Installation of the High Momentum Particle Identification Detector (HMPID) is almost complete and commissioning will start after Easter One Transition Radiation Detector (TRD) Supermodule (SM) has been installed already in 2006 and it is planned to install two more SMs before the 0.9 TeV LHC run in The schedule for this is very tight. During installation of the first two SMs of the Time-of-Flight (TOF) detector inside the L3 magnet some mechanical redesign of the support rails became necessary. The present schedule foresees installation of five further TOF SMs before closing the L3 magnet in summer Installation of the tracking and trigger chambers of the Dimuon Spectrometer have started and commissioning is ongoing in parallel. Production of electronics is proceeding well. In summary, the LHCC identified no major concerns in the areas of the particle identification and the Dimuon Spectrometer. Realisation of the ALICE Forward Detectors - V0, T0, Forward Multiplicity Detector (FMD), Photon Multiplicity Detector (PMD) and the Zero Degree Calorimeters (ZDCs) - is advancing well and the hardware construction is on track. In the case of the PMD, not all electronics may be ready for the LHC engineering run in 2007, but this will not have a lasting impact. The Photon Spectrometer (PHOS) group is ready to install one module, and the funding is now secure for a further two modules to be ready for the 2008 run. The Electromagnetic Calorimeter (EMCAL) support structure is ready but is delayed in shipping. The latter is not yet a concern but the structure s delivery to CERN cannot be delayed by more than six weeks from now. Deployment, integration and pre-commissioning of the Trigger, High-Level Trigger, DAQ and Controls systems are progressing well. The integration process has gained considerable momentum over the last months, though due to the complexity of the experiment, the time scale is nevertheless tight. In the offline sector, sizeable efforts are ongoing to prepare the software for real data, which need stronger support from sub-detector and physics groups. While the balance of pledged computing resources within the World-wide LHC Computing Grid (WLCG) has improved, there are still shortfalls expected in 2008 and beyond. Good progress was reported on the installation and commissioning of the ALICE detector. The LHCC noted the late installation of the Miniframe, which carries services without which commissioning of the sub-detectors cannot be completed, the availability of power supplies and the integration of the experimental control system with the sub-detectors. In order to make most of a cosmic-ray run, the LHCC

6 6 recommends that ALICE clarifies the aims of such a run and subsequently appoints a run manager for this period. The LHCC considers that the strategy for data-taking, alignment and calibration presented by ALICE is reasonable and no major issues were identified. The LHCC reviewed the ALICE physics programme for the 0.9 and 14 TeV protonproton runs, and for a PbPb pilot run. The proton-proton programme has the right degree of realism and ambition, with measurements of inclusive properties of the final states apt for a tuning of Monte Carlo tools, as well as studies of the dynamics of very high multiplicity final states and of possible benchmarks for PbPb observables. A few days of low-luminosity PbPb data taking will provide a very valuable sample of events, with which to start the core programme of ALICE by determining global event properties and measuring the first hard-probe observables. The LHCC took note that several new institutes have recently joined or are about to join the ALICE Collaboration, bringing with them valuable resources and expertise. Good progress was reported on securing funding for the Electromagnetic Calorimeter (EMCAL), the Photon Spectrometer (PHOS) and for the Transition Radiation Detector (TRD). The Collaboration continues to adopt measures to control increases in the cost-to-completion. 10. REFEREES Following changes to the LHCC membership, the new referee teams are as follows: ALICE: P. Dauncey, M. Gonin, J. Haba (Co-ordinator) ATLAS: F. Forti, V. Kekelidze (Co-ordinator), M. Martinez-Perez, P. Mato CMS: S. de Jong, R. Mankel, S. Smith (Co-ordinator), R. Yoshida LHCb: S. Dalla Torre, C. Niebuhr, B. Peyaud (Co-ordinator) TOTEM: S. Dalla Torre MOEDAL: B. Peyaud LHCf: M. Mangano, C. Niebuhr RD39: S. de Jong RD42: V. Kekelidze RD50: R. Yoshida LCG: P. Dauncey, F. Forti (Co-ordinator), R. Mankel, M. Martinez-Perez 11. DATES FOR LHCC MEETINGS Provisional Dates for 2007: 9 10 May 4 5 July September November

7 7 12. The LHCC received the following documents: Early TOTEM Running with the 90m Optics LHCC G-130 CMS Expression of Interest in the SLHC LHCC /G-131 CMS Physics: Technical Design Report v. 2: Addendum on High Density QCD with Heavy Ions LHCC /TDR-8.2-add.1 LHCb Comprehensive Review Report, 7 February 2007* LHCC /G-126 Minutes of the eighty-sixth LHCC meeting held on Wednesday and Thursday, 31 January & 1 February 2007 CERN/LHCC /LHCC 86 *restricted circulation Emmanuel Tsesmelis Tel , E mail:lhcc.secretary@cern.ch LHCC Secretariat: Morna Robillard (Bldg. 14/4-022) Tel morna.robillard@cern.ch