CERN/LHCC 2001-016
LHCC 52
21 May 2001
LARGE HADRON COLLIDER COMMITTEE

Minutes of the fifty-second meeting held on
Wednesday and Thursday, 16-17 May 2001

OPEN SESSION:
1.    CMS Status Report: M. Della Negra

2.    Heavy-ion Theoretical Perspectives for RHIC and Implications for the LHC Programme: B. Müller

3.    The RHIC Heavy-ion Experimental Programme: J. Harris


CLOSED SESSION:

Present: R. Cashmore, D. Cassel, J. Dainton, J. Engelen (Chairman), A. Ereditato, G. Goggi*, J.-J. Gomez-Cadenas, M. Hauschild, H. Hoffmann*, Y. Karyotakis, J. Lee-Franzini*, B. Löhr, B. Lofstedt*, M. Mangano*, J. Nash, J. Panman, K. Potter, L. Robertson*, P. Roudeau, H. Schellman, D. Schlatter* (replacing G. Goggi), K. Tokushuku, E. Tsesmelis (Secretary), G. Zech.   *) Part timeApologies: P. Lebrun, L. Maiani

1.   INTRODUCTION

The minutes of the fifty-first LHCC meeting (LHCC 2001-008/LHCC 51) were approved with the following modification: in point 2 (report on the ATLAS general schedule), the fourth sentence should be replaced by: `The LHCC takes note that the schedule is known to be limited by resources in certain cases, both in terms of money for installation contracts and in terms of expert manpower available from collaborating institutes for parallel installations.í
The Research Director for Collider Programmes reported on issues being considered by the Resource Review Boards (RRBs). The completion plans and the resources required to realize the experiments will be discussed at the next RRBs in October. As part of the regular reports from the LHCC to the RRBs, which provide a summary of the principal deliberations of the Committee, the LHCC is asked to provide an evaluation of the soundness and feasibility of these plans. Moreover, the LHCC `COREí group will appraise the costs required to complete the experiments. In addition, the RRBs are evaluating the required funds to cover the maintenance, operation and computing costs of the LHC experiments. Together with the principal contracts for the LHC Machine, this information will be presented subsequently to the CERN Council, thus providing an evaluation of the whole LHC programme.2.    REPORT FROM THE ALICE REFEREES The LHCC heard a report from the ALICE referees, concentrating on the overall status, a more detailed presentation on the trigger by B. Lofstedt, who is acting as a consultant, status reports on the TPC, TRD and computing, and a presentation on the review of the ALICE Addendum to the Dimuon Forward Spectrometer TDR.

The referees reported on their review of the Addendum to the Dimuon Forward Spectrometer TDR. The Addendum details the design modifications to the tracking chambers, and the resulting integration and overall performance issues. It also provides a status report of the associated detector sub-systems and introduces the conceptual design of the newly-proposed V0 detector, whose aim is to reject background events produced in the LHC machine during pp running.

ALICE is currently preparing the User Requirement Document (URD) for the trigger. In preparing the URD, the LHCC asks the Collaboration to develop a scheme elaborating which detectors will be included in the trigger. The final URD is planned to be available in October. Moreover, a substantial increase in the size and complexity of the Central Trigger Processor was reported. This would result in the need of additional resources, both in terms of money and manpower. Finally, delays of at least 8 months were reported on all milestones for the Central Trigger Processor, but the LHCC considers that the delays are not yet critical for the commissioning of the sub-detectors.

The calendar for submission of ALICE documents is the following: the TRD TDR will be submitted in time for the October LHCC, the Addendum to the TOF TDR and the Computing Technical Proposal in the second half of 2001, the Trigger/DAQ TDR towards the end of 2002 and the Physics Performance Report in 2002, allowing inclusion of the studies and conclusions of the workshop on heavy-ion physics at the LHC. The LHCC considers this schedule to be reasonable.

3.    REPORT FROM THE ATLAS REFEREES The Committee heard a report from the ATLAS referees, concentrating on the progress of the detector construction, the follow-up to the discussion on the RPCs, the review of resources and preparation of the ATLAS Comprehensive Review to be held on 2-3 July.

Taking into account the technical constraints as well as the available resources, the Collaboration is working on a plan of the detector lay-out for the initial running of the LHC which will allow the experiment to search for the Higgs and SUSY particles. The limitations and shortage in resources, both in terms of money and in terms of expert manpower, are being discussed with the relevant funding agencies. A progress report will be given to the ATLAS Resource Review Board in October.

The referees also reviewed the ATLAS RPCs. Ageing tests in the Gamma Irradiation Facility (GIF) on chambers coated with a few microns of polymerised linseed oil show encouraging results. Although the module tested experienced an increase in noise after an irradiation campaign equivalent to operating ATLAS for 12 years, the chamber still exhibits a functionality that is within the ATLAS requirements. To conclude, the referees found no evidence that the ATLAS RPC chambers will develop problems as long as they are operated according to their design specifications.

4.    REPORT FROM THE CMS REFEREES The Committee heard a report from the CMS referees, concentrating on the review of the CMS milestones, and the progress on computing and on the HCAL.

The referees reported on the draft of the updated CMS milestones. The list of milestones has been updated in order to bring the overall CMS schedule in line with the new LHC Machine schedule. This list will be finalized in June and communicated subsequently to the LHCC in its final form.

The referees also reviewed the CMS computing and software. In an effort to bring the computing management together, CMS has set up a new group called CPT, consisting of the three entities Core Computing Software, Physics Reconstruction Selection and TRIDAS. The referees also noted the shortage in expert manpower for computing and funds for driving large scale tests. Memoranda of Understanding for the computing needs of the LHC experiments will be required to be signed with the funding agencies in the future. Finally, a clearer understanding of how the LHC experiments can fit into the developments of the computing GRID is required.

The referees also reviewed the status of the HCAL. Good progress was reported on the HB mechanics, readout box, optical components and front-end electronics. Application of an anti-reflective coating is thought to solve the problem with optical cross-talk in the HPDs. The HPD production remains critical but recovery of the schedule is possible albeit with additional money. The complete QIE has been submitted in March and is due back in June. The production of the QIE is expected to be completed in July 2002. Good progress was also reported on the HE. The decision to have the HF ready for the first physics run means that it must be the first sub-detector to be installed in the underground experimental cavern. However, the schedule is very tight. Moreover, the available funding does not completely cover the cost of the HF and Collaboration is studying possibilities for cost savings by staging the longitudinal segmentation. A decision will be taken by CMS in June and the LHCC asks to be kept informed of progress.

5.    REPORT FROM THE TOTEM REFEREE The LHCC heard a report from the TOTEM referee. Measurements of the elastic and inelastic rates will be performed by the experiment. The former will be made using Roman Pots, most probably based on cryogenic silicon detectors. The measurement of the inelastic rate will be made with telescopes that cover the pseudorapidity interval 3 < h < 7 and consist of CSCs for tracking and RPCs for triggering. The referee discussed the integration issues with CMS and with the LHC Machine, concluding that they are progressing satisfactorily. Moreover, a CMS/TOTEM Luminosity Working Group has been set up in 1999 to develop a strategy for the measurement of luminosity at CMS. CMS has also shown interest in diffractive measurements using the TOTEM set-up. To this end, it was shown that the TOTEM detector can be integrated into the CMS Trigger/DAQ and the CMS detector can be read out on the occurrence of a TOTEM trigger. The final design of the TOTEM detectors and interface to the neighbouring systems will be presented in their TDR, scheduled to be submitted to the LHCC by the end of 2001.6.    ALICE ADDENDUM TO THE DIMUON FORWARD SPECTROMETER TECHNICAL DESIGN REPORT The LHCC has completed its scientific, technical and cost evaluation of the ALICE Addendum to the Dimuon Forward Spectrometer TDR submitted in December 2000. The Committee was impressed by the quality of the work presented in the Addendum and congratulates the Collaboration. The optimisation of the design of the tracking chambers relative to the TDR increases their acceptance and enables the chambers to cope with higher rates.

The Committee considers the proposed modifications to the tracking chambers appropriate to improve the performance of the Dimuon Forward Spectrometer. The Committee has no major concerns. An ancillary document (LHCC 2001-017) 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. It is recommended that ALICE conducts an independent review of the engineering design. Written reports should be made available to the LHCC through its referees.

Recommendation

The LHCC recommends general approval of the ALICE Addendum to the Dimuon Forward Spectrometer TDR. The LHCC considers the schedule given in the Addendum 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 LHCb REFEREES The LHCC heard a report from the LHCb referees, concentrating on progress towards the submission of the TDRs for the Vertex Locator (VELO) and Muon detectors, updates on the status of the sub-systems and the overall status of the experiment.

Good progress was reported on the silicon technology and LHC machine integration issues for the VELO. The recent Engineering Design Review of the system, held in conjunction with the LHC vacuum group, concluded that the present design of the VELO is sound and acknowledges the efforts made to reduce the risks to the operation of the LHC. The referees also reported good progress on the Muon system.

The referees reported that LHCb decided to remove the station T11 of the tracking system designed for the RICH-2 detector. This station would provide a better resolution of the track angle measurement at low momenta but it was found not to be important enough for the RICH-2. By removing it, the RICH-2 can be extended resulting in more Cherenkov photons. The LHCC requests a detailed report on the decision, at which point it will consider whether an addendum to the approved RICH TDR is needed.

Finally, the referees reported on the LHCb milestones. None of the known delays appear to be critical. LHCb is still committed to be ready for installation in mid-2004.

8.    DISCUSSION ON RESISTIVE PLATE CHAMBERS Following the preliminary discussion on RPCs at the March session of the LHCC, the Committee this time reviewed the available information and provided its conclusions and recommendations. The Committee recommends that all LHC experiments produce a detailed document illustrating the individual tasks to be undertaken in the manufacturing phase of the RPCs. The report should also address Quality Assurance and Control. This document should be reviewed within each of the experiments and should also be communicated to the LHCC. The LHCC will use this information to review and monitor the production of the RPCs. The task list should also serve as a basis to prepare the Memorandum of Understanding with the manufacturing firm. The LHCC also recommends that the experiments should not move hastily into production of the chambers before ensuring both their functionality and the manufacturing process. The LHCC will continue monitoring the progress in the RPCs.9.     DISCUSSION ON THE LHC COMPUTING REVIEW Following the preliminary discussion on the LHC Computing at the March session of the LHCC, the Committee this time reviewed the available information and provided its conclusions and recommendations. The recommendations of the LHCC have been performed with L. Sarlo of the European Meteorological Satellite Organisation (EUMETSAT) acting as a consultant. The LHCC endorses the conclusions of the LHC Computing Review, which was held under the chairmanship of S. Bethke. It considers that the review has set out a sound model for the future LHC computing and it identified a potential lack of resources. To this end, the Review has helped inform the scientific community of the importance of computing at the LHC and has also built-up momentum in attracting additional funds to ensure that the required manpower, equipment and large-scale prototypes can be realized. The LHC Computing Review has recommended the instigation of the LHC Software and Computing Steering Committee (SC2) to oversee the deployment of the entire LHC hierarchical computing structure, and the LHCC concurs with this conclusion as the next step forward.10.   TEST BEAMS M. Hauschild presented a status report on the SPS and PS Fixed Target Programmes. He reported on the physics programme at the PS East Hall, which started on 2 April, and stated that the SPS programme is on schedule to commence in July. He also discussed the implications of the new HARP proposal to run in 2002 with both proton and He++ beams. This would delay the transfer of the T9 beamline currently used by HARP to LHCb and running with He++ would exclude the parallel running of the other beamlines in the PS East Hall. A discussion will be held in the upcoming SPSC, with the final decision to be taken at the next Research Board.11.  DATES FOR 2001 LHCC MEETINGS 4-5 July

3-4 October

21-22 November

The LHCC received the following documents