Minutes of the thirty-fifth meeting held on Thursday and Friday, 9-10 July 1998


1. Status of the LHC project: C. Llewellyn Smith

2. ATLAS Level-1 Trigger Technical Design Report (LHCC 98-14): N. Ellis, E. Petrolo, E. Eisenhandler

3. ATLAS Pixel Technical Design Report (LHCC 98-13): L. Rossi

4. RD42 status report (LHCC 98-20): H. Kagan


Present: B. Adeva, G. Altarelli, J. Carr, R. Cashmore, J. Engelen (Chairman), A. Ereditato, L. Fo, B. Foster, D. Hartill, M. Kasemann, R. Kephart, H. Kolanoski, S. Komamiya, C. Llewellyn Smith*, L. Maiani*, J. May, M. Mazzucato, N. McCubbin, A. Menzione, K. Potter, A. Read, G. Rolandi, A. Rostovtsev, M. Spiro, E. Tsesmelis (Secretary), H. Wenninger*

Apologies: L. R. Evans, G. Goggi, A. Schwarz, D. M. Sendall, P. Sharp

(H. Dijkstra and R. Forty were present for point 4. J. J. Blaising was present for point 6.)

1. The minutes of the thirty-fourth LHCC meeting (LHCC 98-18 / LHCC 34) were approved without amendment.


The LHCC has completed its scientific, technical and cost review of the CMS Tracker TDR, which was submitted in April 1998. The committee is impressed by the quality of the work in the TDR and congratulates the collaboration. The TDR describes a coherent tracking system, which can provide adequate track finding capabilities for the LHC physics.

There are, however, two major concerns:

1. The committee notes that the MSGC system cannot yet be considered completely proven for the LHC environment. Appropriate steps and milestones for verifying this technology have been discussed with the collaboration.

2. The funding presently available has obliged CMS to adopt a two-stage approach to the complete tracker. If this situation should persist, the committee considers that there are serious issues arising from this staging which require optimisation.

These concerns are discussed in more detail in an ancillary document (LHCC 98-25) which also contains a list of agreed milestones.

The LHCC review was not an engineering review of the tracker, although the work done in this area was noted. It is recommended that CMS conduct independent reviews of the engineering designs including all aspects of the system. Written reports of these reviews should be made available to the LHCC through its referees.


The LHCC recommends general approval of the CMS Tracker Technical Design Report describing design, performance, construction and installation in early 2005. The review identified two major concerns that require attention. The LHCC considers that the schedules given in the TDR and the milestones in the ancillary document are reasonable. They will be used by the committee to measure and regulate the future progress of the project.


H. J. Hilke reported on the evaluation by CORE of the CMS Tracker project. Based on the TDR and an updated cost-planning document, CORE prepared a number of questions for the collaboration, and received written answers. These have been discussed with the collaboration. CORE appreciates the care taken in preparing the cost review and the help provided by the collaboration in the evaluations. In most cases, estimates now have a firm basis in industrial offers and prototype costs. The 1998 total cost ceiling is in line with the previous assessment, even though there have been significant changes to the sub-system estimates. CMS has adopted cost ceilings for each major component.

CORE considers that the cost estimates for the CMS Tracker are reasonable and fit within the overall envelopes of CMS cost estimates: the LHCC endorses this evaluation.


T. Nakada and H. J. Hilke gave a report on LHCb, covering the CP physics programme of the experiment, recent developments on detector R&D, installation planning, milestones and costs. Due to its efficient trigger for both leptons and hadrons, its particle identification capabilities and its good decay time and mass resolutions, LHCb would provide the required precision for studying CP violation in the B meson system. The collaboration has agreed to also submit a TDR for the magnet system. There has been no change to the total cost of the experiment since the submission of the Technical Proposal and the CORE document has been submitted.


The LHCC congratulates the collaboration on the substantial work represented by the LHCb Technical Proposal.

The committee is convinced that the LHCb Technical Proposal is sound. Further, the reach in B physics with the proposed detector in CP violation and rare decays appears to be significantly larger than either the B-factory detectors or ATLAS and CMS at the LHC.

Accordingly, the committee recommends general approval of the LHCb Technical Proposal (CERN/LHCC 98-4/P4) subject to the successful completion of the pending CORE review. A copy of the detailed recommendations (LHCC 98-23) to be sent to the Director General is attached to the minutes.


The committee heard a report from the ATLAS referees, concentrating on preliminary reactions to the Technical Design Reports for the Pixel and Level-1 Trigger systems. A reviewing schedule has been agreed and the referees plan to make a further report at the next meeting of the LHCC. C. Damerell and A. Menzione were consultants for the pixels and J. J. Blaising and D. Ressing were consultants for the level-1 trigger.

The LHCC also discussed the document describing the material budget of the ATLAS Inner Detector (LHCC 98-17). This document was requested by the LHCC at the time of approving the inner detector TDR because of concerns that a further increase in the amount of material might compromise the performance of the electromagnetic calorimeter for the two physics benchmark channels H 4e and H gg.

The committee recognises the quality of the work represented by this document and appreciates the optimisation process. The present improved design of the inner detector shows no further increase in terms of radiation length thickness. It keeps the additional tails in the energy response of the electromagnetic calorimeter due to material to below 10% for H 4e and to below 4% for H gg, while preserving the pattern recognition, B physics capabilities, robustness and reliability of the detector.


The committee heard a report from the ALICE referees, reviewing the status of the R&D on the muon-arm tracking chambers and on the PHOS detector. Several 1 m2 prototype muon chambers will be evaluated during 1998 and the PHOS energy resolution is now close to the design value. The referees also confirmed the schedule for the submission of the ALICE TDRs.


The committee heard a report from the MOEDAL referee, concentrating on further reactions to the MOEDAL Letter of Intent. There are still some pending questions, which the referee will convey to the collaboration. The committee will ask the MOEDAL collaboration to make a presentation on their proposed passive search for highly ionising particles at the next open session of the LHCC.


E. Tsesmelis presented the status of the SPS and PS programmes. First beams for physics in the upgraded PS East Hall were expected on schedule. He then outlined various scenarios for the schedule of the accelerators for the years 1999-2002 in order to initiate a discussion.


The LHCC received the following documents:

ATLAS Collaboration: Pixel Detector Technical Design Report (LHCC 98-13/TDR11)

ATLAS Collaboration: First-Level Trigger Technical Design Report (LHCC 98-14/TDR12)

ATLAS Collaboration: Trigger Performance Status Report (LHCC 98-15)

ATLAS Collaboration: DAQ, EF, LVL2, and DCS Technical Progress Report (LHCC 98-16)

ATLAS Collaboration: The Material Budget of the ATLAS Inner Detector (LHCC 98-17)

RD42 Collaboration: Status Report LHCC / RD42 (LHCC 98-20)

CMS Referees: Review of the CMS Tracker Technical Design Report (LHCC 98-25)*

* Restricted circulation only

LHCC Secretariat: Janet Grant (Bldg. 14/4-022) Tel. 73424,  Janet.Grant@CERN.CH