Minutes of the sixty-fifth meeting held on
Wednesday and Thursday, 2-3 July 2003
1) CMS Status Report:
2) Status of the CMS Magnet: Alain Hervé
3) Prospects for Dark Matter Searches in CMS: Marco Battaglia
4) Prospects for Dark Matter Searches in ATLAS: Daniel Tovey
Apologies: J. Dainton
The minutes of the sixty-fourth LHCC meeting (LHCC 2003-024 / LHCC 64) were approved without modification.2) INTRODUCTION
He reported on the CERN Council meetings of June 2003.
CERN's Director General, Professor Luciano Maiani confirmed that, although
there remain hurdles to overcome, LHC operation will start in spring 2007.
Professor Maiani also drew attention to the need to renovate infrastructure,
some of which has been providing reliable service since the late 1950s, as an
urgent measure necessary for the success of the LHC. CERN Council approved the
Medium Term Plan for the years 2004 —2007 and approved the creation of a new
category of locally recruited staff in Career Paths A and B as of 1 July to
fulfill the Organization's needs for technicians and administrative personnel
and to resolve a long-standing legal problem. Director-General elect
Dr. Robert Aymar presented his proposal for a new organizational structure for CERN from 1 January 2004 when he takes office. The new structure is intended to ensure continuity and build on existing strengths at CERN, while at the same time implementing changes at the higher levels appropriate to CERN's current objectives. The main features of the structure are short lines of management and a restricted directorate consisting of Dr Aymar, a Chief Scientific Officer, Professor J. J. Engelen with functions of Deputy Director General, and a Chief Financial Officer,
Mr A. J. Naudi. CERN's current Divisions will be regrouped into a smaller number of Departments, while functions including safety, technology transfer and public communication will be moved into the Director General's Office.
Moreover, Professor Cashmore reported that the Research Board at its meeting held on 5 June 2003 approved the CMS Trigger and Data Acquisition Technical Design Report.
The Committee took note of the September 2003 review of the computing resources for the LHC experiments. The primary objective of the review is to scrutinise the required and available manpower for the core and sub-detector software in the experiments and its relation to the LCG Project in order to evaluate whether the experiments are putting the correct effort into this computing.
The next Installation Reviews of the LHC experiments will
be held on
8-10 September 2003.
The referees reported on the critical issue of the interface between the HLT and the DAQ. An architecture for the HLT-DAQ interface has been agreed to by the respective HLT and DAQ projects. A formal document is under preparation, which includes the financial arrangements, and will be discussed in the July 2003 ALICE Management Board. Although ALICE is on track to submit a common Trigger/HLT/DAQ Technical Design Report at the end of 2003, the LHCC reiterated its concerns regarding the critical interface issues expressed at previous meetings of the Committee.
The LHCC also heard a report on the status of the TPC. Concern was expressed on the delays caused by leaks in the inner field cage and on the tight schedule for the resistor rods and the TPC electronics while progress was reported on the Readout Chip and the Readout Control Unit. Although the mechanical installation underground remains unaffected, the overall schedule for the surface works has been delayed by 7 months, thus reducing from 13 months to 6 months the time for pre-commissioning the TPC on the surface starting in 2005. The Committee also took note of the need to re-design the TPC cone to allow for the Photon Multiplicity Detector (PMD) acceptance. The LHCC will continue monitoring the progress at future meetings, as it considers that there are several critical issues to be resolved during the course of 2003.
The referees also reported on the status of several of the other sub-systems. Progress was reported on the HAL25 read-out electronics for the Silicon Strip Detector (SSD) as the problem with the low yield has been traced to the metallisation process at the foundry. An engineering run is presently in progress and the LHCC awaits a report on the findings from this latest run. The Silicon Pixel Detector (SPD) is on track for a timely completion. Production of Transition Radiation Detector (TRD) chambers and radiators has started while beam tests show that the ASIC-based electronics for the Time-of-Flight (TOF) operate according to specification. The Committee took note of administrative delays leading to the critical issues concerning the magnet for the muon spectrometer, consisting of delays in the delivery of the magnet yoke, the pause in production of the absorber and the critical timescale for completing the muon wall since it is needed at CERN by spring 2004 for the mapping of the magnetic field.
Excavation of the UXC55 and USC55 caverns is complete and with the ensuing concreting advancing well. A 2-month delay has been reported in the UXC55 cavern due to the increase in the steel reinforcement. Preparations are underway to repair the PM54 and PX56 access shafts following the water ingress and to mitigate the delay in equipping the USC55. The goal is to contain the delay in the latter to at most 2 months but this will require additional resources.
The construction of the magnet is proceeding well but remains on the critical path. More coupling of activities at ANSALDO are being put into place in order to decrease the length of operations at CERN. The goal is to delay the start of the magnet tests on the surface by a maximum of two months, namely to commence on 1 March 2005. This 2-month slip can be integrated in the CMS Master Schedule by limiting the magnet tests underground to only a cryogenic test.
The LHCC heard a report on the ECAL. Crystal production remains on the critical path following the recent delays in delivery. Discussions are on-going with the producers and the LHCC requests details on the revised schedule for the ECAL barrel and end-cap and on the implications of the delays at the September 2003 CMS Comprehensive Review. The choice for the Very Front-end electronics is on track for a decision in July 2003 following which production will be launched in October 2003. The schedule for completing production of the electronics remains aggressive.
The LHCC reiterated its concerns regarding the Silicon Strip
Tracker. Owing to a
5-month delay in the start of series module production, the 3-month contingency allocated in the production and assembly schedules have been used up and the schedule remains tight. The delay requires full exploitation of the production capacity to recover.
The Committee also heard reports on various other sub-systems. Good progress was reported on the Barrel and Endcap Muon Systems. The latter are on schedule, while the former are also advancing well and are expected to be back on schedule by May 2004. The first tests in an LHC-type structured beam in the spring 2003 were successful and additional tests with such beams are needed in early 2004. Good progress was also reported on the HCAL.
The next CMS Comprehensive Review will be held on 22-23 September 2003.
The LHCC took note that the LHCb Technical Board has endorsed the change of baseline for the RICH photon detector from HPDs to MaPMTs with the BEETLE read-out electronics. Although the final decision will only be taken in September 2003, LHCb is already re-directing effort towards the new baseline. The LHCC requests that the new group organisation, together with the new schedule and milestones, be communicated to the Committee following the final decision. The Committee encourages the group working on the HPDs to nonetheless complete the development of these devices.
The referees also reported on the choice between MWPC and Triple GEM detectors for the muon M1 inner region. The key issues driving the choice are the high particle rates (up to 460 kHz/cm2) and the ageing properties of the detectors. In view of the latter, the LHCC recommends that LHCb continue the ageing tests for both options, including exposure to high intensity hadron beams. Although the decision for the technology is now due, it has been delayed to September 2003 with no impact on the overall schedule. Submission of the LHCb Addendum to the Muon System Technical Design Report will follow thereafter.
The LHCC also took note of the good progress on the design and choice of sensor for the TT station. The development programme is advancing well and the milestones are being achieved. The TT system will be described in the LHCb Detector Re-optimisation Technical Design Report to be submitted in September 2003.
The problems with the steel plates for the magnet yoke were reviewed. As the plates are bent, being outside specifications by up to 30 mm, corrective measures need to be taken which include the production of additional assembly tooling. The LHCC milestone of having the yoke assembly completed by September 2003 will be missed and is now expected for December 2003 resulting in a reduced time for testing and field mapping. The first coil has been tested with 1000 A and the resistance measured is as expected.
Finally, the referees reported that submission of the LHCb Detector Re-optimisation and Trigger Technical Design Reports are on schedule for the September 2003 LHCC session.
He reported on the successful irradiation campaign for the CMS ECAL crystals using relatively low intensity proton beams at the PS East Hall and the LHC-type structured beam at the SPS at the end of May/beginning June 2003. In both cases, the conditions provided by the accelerator complex were excellent and the LHCC congratulates the PS and SPS crews. Although several of the LHC detector sub-systems took useful data with the LHC-type structured beam, a number of sub-detectors observed problems which hindered the completion of their programme.
The Research Board approved a 2-week extension to the SPS proton run in order to compensate for problems at the start-up of the SPS in May 2003 and a call for requests for the September 2003 extension period has been issued. A possible second run with the LHC-type structured beam in September 2003 needs to be well-justified by the LHC experiments as any such run would not allow the SPS experiments NA48/2 and COMPASS to take physics data. A sub-group of the LHCC referees will investigate the need for such a second run and a decision will need to be made by the end of July 2003.
Finally, the SPS and PS Coordinator outlined the first lay-out for the 2004 PS and SPS runs. The former would consist of a 24-week run as in 2003, while the latter would consist of a 22-week normal proton run plus 2 weeks with LHC-type structured beam, perhaps separated into two periods of one week towards the beginning and one at the end of the SPS proton run.
It is realistic to expect ATLAS to have an initial working detector for the start of LHC operation in April 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 Barrel Toroid Magnet, the SCT Endcap A, the TRT End-cap A, the LAr EM Barrel, and the LAr 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 April 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 design and testing of the front-end electronics has in general been successfully completed but concerns remain on the procurement of the DMILL electronics from ATMEL for the SCT ABCD, TRT ASDBLR and the LAr calorimeters.
The fourth of the LHCC Comprehensive Reviews of ATLAS took place on 30 June - 1 July 2003. The LHCC referees addressed the following areas: Inner Detector, LAr Calorimeter, Tile Calorimeter, Muon Spectrometer, Trigger/DAQ/DCS, Computing and Software, Physics Studies and the topics of Management, Technical Coordination, Integration, Schedules and Costs.
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.
LHCC Secretariat: Janet Grant (Bldg. 14/4-022) Tel. 73424