LARGE HADRON COLLIDER COMMITTEE
Minutes of the fifty-seventh meeting held on
Wednesday and Thursday, 13-14 March 2002
1. Measurement of CP Violating Asymmetries with the BaBar Detector: Fernando Ferroni (ppt), (pdf)
2. Results and Prospects of the Belle Experiment: Alexander Bondar
3. RD42 Status Report: Harris Kagan
4. ATLAS Trigger Rates and Associated Physics Performance: Stefan Tapprogge
5. CMS Trigger Rates and Associated Physics Performance: Paris Sphicas
The LHCC Chairman welcomed the new Chairman of the Scientific Policy Committee, J. Feltesse, who will be attending selected sessions of the LHCC as an observer.
The Research Director for Collider Programmes reported on the status of the LHC programme. The long-term plan for the laboratory for the years 2003-2010 is being currently developed and includes the schedule and financing of the LHC. The ingredients of the plan will be presented to the Committee of Council in March and a final version will be presented to the June session of Council.
ATLAS has been asked to provide to its upcoming Resource Review Board the configuration of their initial staged detector given that the total ATLAS requests for supplementary funds to ensure completion and pre-operation costs are available in full but only by 2007 or are available only partially by 2007. Two scenarios have been studied. In the case of 80% of the supplementary funding being available, the ATLAS detector is expected to perform near the level of the fully-funded initial staged detector (Higgs significance reduced by about 10%) but will be commissioned under much more restrictive conditions and with higher risks of failure as there would be reduced testing during the commissioning phase. In the case of less resources, very severe cuts into the main physics potential would occur.
A new ATLAS installation schedule (Version 5) is now in preparation with the aim of submitting it to the Collaboration for approval in Summer 2002. A preliminary version of the schedule will be available for the July LHCC Comprehensive Review of ATLAS.
Concerning the barrel-toroid magnet, the firm contracted to perform the integration of the coils into the casings claims to have underestimated the work and requests an additional payment to complete the job. ATLAS has commenced planning for a possible cancellation of the contract and is considering doing the integration work at CERN. The incurred 3-month delay is expected to be caught up by adding extra shifts.
The referees reported on the status of the Tracker. Good progress was reported on the development and procurement of the hybrids for the Tracker M200 tests planned for later this year. Moreover, the effects related to Highly Ionising Particles have been understood and have been quantified to occur at a rate less than 0.05%. Further understanding has also been demonstrated concerning the pin-hole effect and is now considered to be well under control.
The referees reiterated their previous concerns on the RPCs. Technical uncertainties remain regarding whether or not the RPCs (barrel and end-cap) will be coated with linseed oil. Some progress is, however, being made on developing a production plan and schedule and on implementing a management structure.
Moreover, a recent review of the CMS ECAL looked into the new management structure of the project and of explored solutions of reducing the cost of the calorimeter. The review concluded on a rationalisation of the electronics components including the reduction of the optical links and the number of off-detector boards, but with the inclusion of new on-detector L1 ASICS electronics. The LHCC requests that CMS submits written documentation in support of these changes, as they represent a significant change from what was approved in the ECAL TDR. This will enable the Committee to evaluate the technical and cost aspects and the impact on the schedule.
Finally, the referees reported on the overall CMS schedule and milestones. A new version of the schedule (Version V33) is under preparation, which has the CMS detector, without the Pixels, completed in the spring of 2007. Good progress was shown in meeting the agreed milestones that expired over the last few months.
On behalf of W. Bartel, the referees reported on the cost evaluation of the LHCb Online System. They reported that the system’s costing is reasonable and that it fits into the overall cost of the experiment. The cost estimate is based on market prices and includes reasonable extrapolation. It also includes about 10% of spare parts and an adequate provision of manpower.
Good progress was reported for the Hybrid Pixel Detector (HPD) prototype for the RICH detector. It was shown to be operational although problems remain with the bump-bonding, something which is expected to be improved with further prototyping. A number of new developments are underway to improve the HPDs, consisting of a new method of preparing the anode, the availability of new LHCb 40 MHz pixel chip wafers, a new carrier and the fabrication of a new test daughter card. The LHCC considers the development of the HPD still to be a concern and will continue monitoring its progress.
The referees also reported that there has been satisfactory progress in meeting milestones.
The Committee has no major concerns. An ancillary document (LHCC 2002-011) 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 independent reviews of the engineering designs. Written reports should be made available to the LHCC through its referees.
The LHCC recommends general approval of the LHCb Online System Technical Design Report. 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.
In order to complete the development of such advanced detectors and given the modest request for resources to do so, the referee recommends that the R&D project be continued in 2002 with the aim of producing pixel diamond detectors and performing a systematic comparison with the corresponding silicon devices. A status report is expected to be submitted to the LHCC in one year’s time. The Committee agrees to the continuation of the project on this basis.
The LHCC believes that adequate test beams are necessary in 2003 and 2004 for all LHC experiments to calibrate the final calorimeter modules, to perform the integration of the modules in the detectors, to validate the latest versions of the front-end read-out electronics and DAQ chain, to monitor the quality of the detector construction and to test the alignment procedures.
The Committee also believes that in the case of ALICE, ATLAS and LHCb, there are no compelling reasons to use test beams in the year 2005. The CMS test beam requirements in the years 2004-2006 are driven primarily by the calibration of the ECAL. The experiments have therefore been asked to proceed with their test beam programme assuming that beam will be available only in 2003, 2004 and 2006, where the operation of the SPS in the latter year is also required to commission the machine as an injector for the LHC. The LHCC expressed some concern on the amount of beam time required by the CMS ECAL in 2004. The Committee will continue monitoring the amount of beam time required for test beams.
The LHCC also recommends keeping the PS Complex operational in 2005 in order for the experiments to be able to perform final tests and calibrations that do not require the higher energy particles available at the SPS.
The second of the LHCC Comprehensive Reviews of ALICE took place on 11-12 March 2002. The LHCC referees addressed the following systems and areas: Inner Tracking System, Particle Identification, TPC, Calorimeters, Dimuon Forward Spectrometer, Forward Detectors, Trigger and DAQ, Offline Software, Physics, Test Beams, and the topics of Management, Technical Coordination, Integration, Schedules and Costs.
The principal 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.
Dates for 2002:
The LHCC received the following documents