CERN/LHCC 2000-030
LHCC 46
2 June 2000

 

LARGE HADRON COLLIDER COMMITTEE

Minutes of the forty-sixth meeting held on

Wednesday and Thursday, 17-18 May 2000



 

OPEN SESSION:
1. ATLAS High-level Triggers, DAQ and DCS Technical Proposal
   (LHCC 2000-017): V. Vercesi and C. Bee

2. RD46 Status Report (LHCC 2000-027): G. Martellotti

3. LHCb Status Report: T. Nakada
 
 

CLOSED SESSION: Present: B. Adeva, G. Altarelli, W. Bartel*, J. Carr, R. Cashmore, D. Cassel, J. Dainton,
M. Delfino, J. Engelen (Chairman), A. Ereditato, G. Goggi, M. Kasemann,
J. Lee-Franzini, B. Lofstedt*, B. Löhr, K. Potter, A. Rostovtsev, P. Roudeau,
T. Ruf, H. Schellman, P. Sharp, K. Tokushuku, E. Tsesmelis (Secretary), G. Zech.

*) Part time

Apologies: L. Maiani, J. May.
 

1. INTRODUCTION The Chairman informed the LHCC that the Research Board, at its 146th Meeting on 13 April 2000, approved the ALICE TDR on their Time Projection Chamber (TPC) under the LHCC formulation which allows the Committee to monitor future progress through the implementation of the schedules and milestones listed in the ancillary document. Moreover, the Research Board approved the LHCb TDR on their resistive dipole magnet.

The minutes of the forty-fifth LHCC meeting (LHCC 2000-021/LHCC 45) were approved without modification.

2. REPORT ON THE LHC PROJECT The Director of Research for Collider Programmes presented the status of the LHC project. He reported steady progress on the construction of the LHC machine, and as has been reported earlier, the LHC ring is scheduled to be closed in July 2005 in order to commence machine commissioning with protons, thus keeping to the approved LHC schedule. He also noted that the PS machine has been successfully converted to the requirements of the injector chain for the LHC. Training quenches on prototype dipole magnets show encouraging results as do the tests on the Short Straight Section. The first of the pre-series magnets are due to arrive at CERN in August 2000, with the delivery of these ninety magnets extending up to mid-2002. A review of the LHC project is planned for the end of 2000 and will consider information on the machine costs, the schedule of the civil engineering, the progress of the experiments and the LEP schedule, which according to the present schedule should be dismantling.3. REPORT FROM THE ALICE REFEREES The Committee heard a report from the ALICE referees, concentrating on the review of the TDR for the Time-of-Flight (TOF) detector with B. Lofsted as consultant for the electronics. The design of the TOF array is based on gaseous multi-gap resistive plate chambers (MRPCs). Particle identification over a large part of the phase space and for various particles is an important design feature. The TOF rapidity acceptance has to be large enough to cover the full central acceptance of ALICE and should cover the hadron momentum range from about 0.5 GeV/c to about 2.5 GeV/c, complementing the HMPID which is specialized for higher momenta.

The referees also reviewed project milestones of the sub-detectors. It was agreed with ALICE that any major change in schedule, responsibility or funding, as well as any detector modification with respect to the TDRs, will require a document to be sent to the LHCC describing the change which will then have to be reviewed by the Committee in the standard way. In general, the ALICE experiment is following the schedule and milestones presented in the respective TDRs.

Some delays were, however, reported for the Silicon Pixel Detector, for the HMPID and for the PHOS detector. For the pixel detector, the choice has yet to be made for the thickness of the sensors while the bonding of the sensors to the chips is now on the critical path. The referees have asked the Collaboration to provide detailed information for the October meeting of the LHCC. Moreover, delays for the HMPID - CsI deposition system - and for the final design of the CPV for the PHOS detector were reported. These two projects are however not on the critical path. It was also noted that the dipole magnet is now on the critical path.

The referees also reported on the ALICE proposal to modify the design and schedule of the Dimuon Spectrometer. The referees consider the proposed changes to be reasonable and could potentially lead to an improvement in the overall detector performance. However, due to the extent of the re-design, the Committee asks the Collaboration to submit by the end of 2000 an Addendum to the Dimuon Spectrometer TDR. The design milestones are now expected to be delayed by about 6 months while at present it does not seem that the production schedule will change. The referees will make a further detailed report at the July meeting of the LHCC.

The referees also presented the summary of the long-term ALICE test beam requirements for the PS East Hall and for the SPS.

4. REPORT FROM THE CMS REFEREES The Committee heard a report from the CMS referees, concentrating on the review of the Addendum to the CMS Tracker TDR. The Addendum describes a tracker based on the all-silicon option. The choice leads to a uniform technology and it is considered that such a tracker will be simpler in many systems aspects. Moreover, the reduction in costs of silicon and the associated electronics appears to make such a choice financially feasible.

The referees also presented the list of updated milestones and reported on the status of the CMS ECAL and Muon detectors. The ECAL crystal delivery from Russia is proceeding satisfactorily while the milestone for the delivery of 1000 crystals from China is likely to be delayed beyond the end of 2000. Extra investment in the crystal manufacturing capacity is nonetheless required in order to complete the barrel ECAL by mid-2005. For the end-cap ECAL manufacture of the supercrystals must be started in 2001 in order to complete the detector in mid-2006. Optimization of the manufacturing and installation schedule is required for the barrel DT detector in order to complete installation on the surface. Production of the end-cap CSCs is ready to start at Fermilab while reasonable progress was reported on the RPC detectors.

5. COSTS ESTIMATES FOR ALICE TOF DETECTOR AND CMS TRACKER W. Bartel reported on the cost evaluation of the ALICE Time-of-Flight (TOF) TDR and on the CMS Addendum to the Tracker TDR. In contrast to other TDRs, where the R&D phase was completed and prototyping had started, the ALICE TOF detector requires a further two years of R&D work. Some uncertainty, especially in the price of the front-end electronics, is therefore inherent in the present cost estimates. The Collaboration has supplied two values for the cost, which they consider to be the upper and lower limits for the TOF system. Only the former ones look reasonable and will have to become the basis of applications for support. The total manpower allocated to the project is considered adequate but the assignment to specific tasks has to be performed.

For the CMS Tracker, the costing is considered sound. There is sufficient contingency in the components to compensate cost overruns on individual items. It was also noted that the design optimization is still in progress and it is believed that it will bring the total cost down to a level well below the assumed ceiling. Some concern was however expressed on the technical feasibility of the proposed scheme to feed the low voltage to the detector module. In case a solution is chosen which includes local power converters, the cost of this item, which represents about 6% of the total costs, will increase. The infrastructure and manpower to build the tracker are available in the collaboration and the cost fits into the overall financing of the experiment

The LHCC endorses these conclusions.

6. ALICE TIME-OF-FLIGHT TECHNICAL DESIGN REPORT The LHCC has completed its scientific, technical, and cost evaluation of the ALICE Time-of-Flight TDR submitted in March 2000. The Committee was impressed by the quality of the work presented in the TDR and congratulates the collaboration. The TDR describes a detector based on Multi-gap Resistive Plate Chambers (MRPCs) whose technology and design are well-suited for the time-of-flight measurement required to separate kaons and protons from pions and which is adequate to achieve the physics goals stated in the ALICE Technical Proposal.

The Committee has no major concerns. An ancillary document (LHCC 2000-031) 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 Time-of-Flight 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.

However, given that substantial R&D remains to be performed to finalize the design of the detector and the front-end electronics, the LHCC requires the collaboration to provide an Addendum to the TDR which should be submitted to the LHCC by 1 June 2001.

7. CMS ADDENDUM TO THE TRACKER TDR The LHCC has completed its scientific, technical, and cost evaluation of the CMS Addendum to the Tracker TDR submitted in March 2000. The Committee congratulates the Collaboration on the significant R&D which led to a clear demonstration of the feasibility of the Tracker using two technologies. The Committee also notes the simultaneous decline in cost of a solution using only silicon detector technology which led to the proposal in the Addendum. The Collaboration is also to be congratulated on the excellent progress which has been made in modifying the design of the Tracker using only silicon detector technology and which has resulted in the preparation and submission of the Addendum.

The Committee finds the proposed solution in the Addendum to be an appropriate way to construct the CMS Tracker. Since the submission of the Addendum, the Collaboration has made good progress towards defining the logistics, the manpower and the time-scales of the project. Improvements in the design which lead to enhanced performance, to more efficient maintenance, and to the possibility of installing the Tracker with only a fraction of detector modules mounted, have been made. A number of questions arising since submission have been answered by the Collaboration to the satisfaction of the Committee. A number of concerns remain, however, which are listed in an ancillary document (LHCC 2000-032). A set of milestones were presented which will henceforth be used to monitor progress on what is considered to be an aggressive schedule.

Following the first considerations of the engineering aspects of the CMS Tracker in this LHCC review, the Committee considers it essential that an independent engineering review be conducted by CMS of the proposed design. Written reports of this review must be made available to the LHCC through its referees.

Recommendation

The LHCC recommends general approval of the CMS Addendum to the Tracker Technical Design Report. 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.

8. REPORT FROM THE ATLAS REFEREES The Committee heard a report from the ATLAS referees, concentrating on the review of the High-level Triggers, DAQ and DCS Technical Proposal. The Technical Proposal documents the well-advanced status of prototyping and planning reached in this field and lists a set of questions to be answered by the forthcoming Technical Design Report. The Technical Proposal represents proof of concept for the ATLAS higher-level triggers, DAQ and DCS. The Committee was impressed by the quality of the work and congratulates the Collaboration. It recommends general acceptance of the Technical Proposal and encourages the Collaboration to proceed towards a Technical Design Report based on the architecture and concepts laid-down in the Technical Proposal.

The referees also discussed the schedules of various sub-systems. The updated ATLAS Master Schedule, giving the detector construction schedule, with the assumption of a six-month delay in the starting date for the installation of the barrel toroids, will be used to monitor future progress. This schedule is made such that a schedule float of four months is allowed at the end of construction and only two months can be directly absorbed within the systems. The baseline ATLAS Installation Schedule is currently under re-examination in order to take into account the updated construction schedule and to explore options for the installation in view of detector components being potentially late.

9. REPORT FROM THE LHCb REFEREES The referees heard a report from the LHCb referees, including a presentation of the general status and milestones. The call for tender for the warm dipole magnet will be launched soon and it is now considered that the magnet is no longer on the critical path. In view of the time gained due to the earlier delivery of the magnet, the Collaboration is studying how to advance the installation schedule of the experiment.

Steady progress was reported on the LHCb RICH and Calorimeter, the TDRs for which will be submitted for the LHCC session in October. Good progress was also reported for the Vertex Detector, Inner Tracker, Outer Tracker and Muon Detector. Finally, significant progress was reported on the Level-0 and Level-1 trigger scheme, resulting in an improved latency and in the choice of hardware and networks.

10. REPORT FROM THE RD46 REFEREE The Committee heard a report from the RD46 referee on the programme of the Collaboration concerning the R&D into high-resolution tracking devices based on capillaries filled with liquid scintillator. The referee summarized the operation principles of the detectors and commented on the various types of Electron-Bombarded CCDs (EBCCDs), read-out devices developed in collaboration with industry. He also showed test beam results of a prototype micro-vertex detector with capillary layers read out with an EBCCD.

The Committee takes notes of the significant progress made in developing these tracking devices and congratulates the RD46 Collaboration. The Committee considers that with the feasibility of capillary detectors having been proved and with the successful demonstration of the EBCCD read-out, the research programme as defined in the original RD46 proposal is deemed to be successfully completed as an R&D project of the LHCC. Any further continuing studies should be under the auspices of the national funding agencies and requests for test beam time at CERN should be submitted to the SPS/PS Coordinator.

11. TEST BEAMS T. Ruf showed the updated schedules of the physics programmes for 2000 at the PS East Hall and at the SPS and discussed the LHC detector tests performed there. He also presented an overview of the long-term test beam requirements of the LHC experiments. In general, more beam time is required, particularly at the SPS, than is presently projected to be available and a general discussion on the sharing of the beam-time between various LHC experiments and with the SPS experiments, including those of a possible future heavy-ion programme at the SPS, is needed.12. ANY OTHER BUSINESS The Chairman provided further details of the new reviewing procedure of the Committee. These Comprehensive Reviews are tailored to cover all major areas of the LHC experiments and aim to facilitate the exchange of knowledge and experience across experiments and between the various referee teams of the LHCC. The detailed agenda for the Comprehensive Review of ATLAS planned for July was presented.13. DATES FOR 2000 MEETINGS 5-6 July

4-5 October

29-30 November
 
 

The LHCC received the following documents * Restricted circulation only.
 
 
 

Emmanuel Tsesmelis
Eómail: LHCC.Secretary@cern.ch
Tel. 78949
 
 

LHCC Secretariat: Janet Grant (Bldg. 14/4-022) Tel. 73424
Janet.Grant@cern.ch