CERN/LHCC 95-37

LHCC 17

8 June, 1995

LARGE HADRON COLLIDER COMMITTEE

Minutes of the seventeenth meeting held on Tuesday, Wednesday and Thursday,
16-18 May 1995

OPEN SESSION :

1. Status of the LHC project (C.Llewellyn Smith)

2. Debye screening in heavy-ion collisions with the ALICE detector (LHCC 95-24; J.Schukraft)

3. Expression of Interest for a "BEAM-DUMP" upgrade of L3 for the LHC (LHCC 95-17 and addendum LHCC 95-22; P.Fisher, J.Kirkby)

CLOSED SESSION :

Present: J.J.Aubert (Chairman), J.Bernabeu, R.J.Cashmore, L.DiLella, P.J.Dornan, P.Duinker, F.Eisele*, J.Ellis, L.R.Evans*, L.Foa, U.Goerlach, G.Goggi, E.Iarocci, P.Igo-Kemenes, K.Kajantie, C.Llewellyn Smith*, H.Montgomery, K.Potter, A.Schopper, K.Schubert, D.M.Sendall (Secretary), M.Turala, D.O.Williams, G.Wormser.

*) Part time

Apologies: C.Dionisi, A.Golutvin, H.Wenninger, S.Yamada

(Members of the LCRB, LDRB and LERB were invited for points 5, 6, 7, 8 and 9. The following were present for part of these: A.Ball, F.Barreiro, W.Bartel, J.J.Blaising, C.Bohm, F.Bourgeois, A.Breskin, J.Dainton, H.G.Fischer, G.Hall, J.Harvey, H.J.Hilke, G.Kellner, U.Koetz, P.Lazeyras, I.Lehraus, M.Mazzucato, R.Mount, M.Mur, E.Petrolo, S.Quinton, W.Smith, G.Stefanini, H.Tiecke, M.Yvert. )

1. The minutes of the sixteenth LHCC meeting (LHCC 95-23 / LHCC 16) were approved without amendment.

2. C.Llewellyn Smith announced that Prof. Enzo Iarocci of INFN Frascati had agreed to take over as LHCC Chairman from 1 October 1995 when the present Chairman's mandate expires.

3. REPORT FROM THE HEAVY ION REFEREES

The heavy ion referees reported on the potential for Debye screening measurements by ALICE, BEAM-DUMP and CMS.

4. BEAM-DUMP REFEREES' REPORT AND CONCLUSIONS

The committee heard a report by the BEAM-DUMP referees, and discussed the expression of interest.

The committee fully appreciates that a measurement of sin2thetaw to 6.10-5 would be a very significant measurement, and that this is the first time this has been addressed.

Nevertheless the committee is not convinced that the suggestions in the BEAM-DUMP expression of interest form the basis of a viable experiment for this measurement.

Particular concerns are:

a) Whether the parton density functions can be determined to the required accuracy, either using the W or from measurements from other experiments.

b) That it is possible to track and trigger on muons in the region 4 < |eta| < 6 and maintain the required mass resolution. Without this region the benefits over the combined results from ATLAS and CMS are not great.

The committee is not prepared to consider further the expression of interest in the absence of satisfactory answers to the above questions. The proponents are invited to discuss with the referees how they might proceed.

5. REPORTS ON DETECTORS, ELECTRONICS AND COMPUTING

The committee heard reports on the status of the R&D programme, in particular as it affects ATLAS and CMS in the light of the technical proposals. The speakers drew attention to a number of areas where further work is needed.

G.Hall reported on silicon detectors. E.Iarocci reported on MSGCs and MGCs. H.Montgomery reported on TRDs. H.Fischer reported on electromagnetic calorimetry. H.Tiecke reported on hadron calorimetry. P.Duinker and E.Iarocci reported on muon chambers

F.Bourgeois reported on the work of the LERB. Recent discussions have covered electronics for Resistive Plate Chambers and the mean timer architecture of the CMS barrel DTBX chambers. Preparations are well in hand for the Lisbon workshop in September.

For the LCRB, J.J.Blaising reported on trigger and data-acquisition. He gave an overview and comparison of the ATLAS and CMS approaches. Studies are well advanced, and the requirements of both architectures appear reasonable in the light of technology trends. Realistic prototypes will be a key element in further progress. M.Mazzucato reported on general computing topics. He outlined plans for a computing technical proposal, based on a computing model and project management plan to be discussed with the LCRB by the end of 1996.

6. REPORT FROM THE LDRB

H.Tiecke presented a report on the work of the LDRB. On the R&D programme, a status report has been submitted by RD-40 and a proposal received (P60).

Status Reports of approved projects presented at the open session

RD-40: Development of quartz fibre calorimetry (LHCC 95-27)

H.Tiecke gave an overview of the project and drew attention to the substantial achievements so far. He reported on the conclusions of the LDRB as presented in LHCC 95-35.

Following the advice of the LDRB, the LHCC recommends the continuation of the project in order to complete the programme of measurements by the end of 1995, with the following goals:

- Fibre irradiations.

- Hadronic calorimeters; measurement programme on energy and position resolution.

- High energy (100 GeV) data point EM calorimeter.

Proposal presented at the previous meeting

P-60: High resolution tracking devices based on capillaries filled with liquid scintillator (LHCC 95-7)

H.Tiecke gave an overview of the proposal and of the status of work in this area. He reported on the conclusions of the LDRB as presented in LHCC 95-32.

Following the advice of the LDRB, the LHCC recommends the approval of the project for a year as regards the part which is necessary to show the feasibility for use of planar detectors in a high rate environment, provided the collaboration can obtain the required support. The following milestones were agreed for the coming year:

- Production of capillary layers, 1-3 mm thick, 4 x 20 cm2. This includes cutting, filling, mechanical quality check, array uniformity, test beam results.

- Test the new capillary bundle with megapixel EBCCD and the new readout electronics (improved signal/noise).

- Final lab tests of VIP 1 microsec.

- Feasibility study VIP 20 microsec.

7. REPORT FROM THE LERB

On the R&D programme, status reports have been submitted by RD-12 and RD-16

Status Reports of approved projects presented at the open session

RD-12: Readout system test benches (LHCC 95-26)

The LERB referee reviewed the activities of the collaboration to date. He reported on the LERB conclusions as presented in LHCC 95-33. The LERB congratulates RD-12 on excellent work and a valuable contribution to the development of LHC readout systems. The LERB considers that some of the work should now be centred on specific projects: Digital Signal Processing algorithms in RD-16 and RD-20, video industry components in CMS level 1 calorimeter trigger, and software tools in CMS. The LERB proposes that further work on dual port memories should devolve on ATLAS and CMS, but intends to review the situation in a year's time. The LHCC agreed with these recommendations.

Following the advice of the LERB, the LHCC recommends the continuation of the project for a further year for the work on Timing Trigger and Control distribution (TTC). The LHCC took note of the recommendations on TTC in LHCC 95-33, and encourages the LHC collaborations to profit from the work of RD-12 in this field.

RD-16: A Digital Front-end and Readout Microsystem for calorimetry at LHC (LHCC 95-28)

The LERB referee gave an overview of the FERMI approach, the organisation of the project and its achievements to date. The LERB recognises the high quality of the work done by the collaboration and the progress made during the last year on all aspects of the project. The referee reported on their conclusions as presented in LHCC 95-34. In looking at the projected 1995-1996 programme, the LERB has tried to separate the work still needed to reach completion of the generic R&D programme from that required to make the transition towards actual applications.

Following the advice of the LERB, the LHCC recommends the continuation of the project for a further year with the following goals:

- Continuation of the work on the ADC circuit, in order to reach the agreed performance figures corresponding to true 10-bit digitisation at 40 M samples per second.

- Assembly, test and qualification of the Multi-Chip Module to assess the proof of principle of the compact system approach. As MCM yield is strongly correlated with the choice of known good dies, the policy to obtain testable chips and the selection procedures should be indicated.

- A representative demonstrator micromodule should be tested under realistic operating conditions.

The LHCC agreed that the other items included in the 1995-1996 programme are more closely related to applications and should be developed in close collaboration with the ATLAS and CMS application teams, who should progressively take over responsibility.

8. REPORTS FROM THE MAGNET ADVISORY GROUP AND ENGINEERING REVIEW GROUPS

P.Lazeyras presented the report of the Magnet Advisory Group (LHCC 95-30). Over the past year, the designs of the ATLAS and CMS magnets have progressed from the conceptual stage and are now entering the engineering design phase. Details of progress were reviewed; time schedules and costs were not discussed, as these are presently under review by both collaborations, with results due by July 1995. The Magnet Advisory Group is of the opinion that the process of review by outside experts should continue until the Critical Design Review stage, when full engineering designs are available for procurement.

P.Lazeyras reported on the work of the Engineering Review Group. Their first report (LHCC 95-31) concentrates on installation; more detailed schedules are expected within a few months. It was agreed that it is too early for an engineering review of the sub-detectors, as little detailed design work has been completed.

9. REPORT ON SAFETY ASPECTS OF THE TECHNICAL PROPOSALS

H.Schoenbacher gave a preliminary report on safety aspects of the ATLAS and CMS technical proposals. Full safety hearings are planned with both collaborations in June.

10. REPORT FROM THE PHYSICS PERFORMANCE REFEREES

The committee heard a report by the physics performance referees covering updated information on the Higgs sector and the potential of ATLAS and CMS for B physics.

11. REPORTS FROM THE ATLAS AND CMS REFEREES

The committee heard reports by the ATLAS and CMS referees on their ongoing work in reviewing the technical proposals. The referees drew attention to a pressing need for strong and centrally coordinated engineering teams.

12. REPORT FROM THE COST REVIEW GROUP

W.Bartel reported on the work of CORE. The essential elements of their report on the baseline designs of ATLAS and CMS were presented: the report will be submitted to the LHCC for their July meeting. He drew attention to some areas of concern where uncertainties in costing have been identified: in some cases projects are not yet completely defined and in others essential R & D remains to be completed. Extrapolation in a rapidly developing market is also a source of uncertainties.

13. REPORT FROM THE B PHYSICS REFEREES

The committee heard a brief status report from the B physics referees.

14. TEST BEAMS

A.Schopper summarised the situation on test beams for LHC activities. Current predictions seem likely to exceed available resources. He pointed out that in the interests of efficiency it is useful to encourage the LHC collaborations to do their own internal scheduling. The LHCC will also need to monitor test beam requests. In order to plan for 1997 input would be needed by the end of 1995.

15. TIMETABLE AND ORGANISATION

The committee held a further discussion of the reviewing process for the technical proposals.

16. DATES FOR 1995 MEETINGS

6-7 July

13-14 September

16-17 November

The LHCC received the following documents

o ALICE collaboration: Debye screening in heavy ion collisions with the ALICE detector (LHCC 95-24)

o RD12 Collaboration: LERB Status Report (LHCC 95-26)

o RD40 Collaboration: LDRB Status Report (LHCC 95-27)

o RD16 Collaboration: LERB Status Report (LHCC 95-28)

o Magnet advisory group: Magnets for the ATLAS and CMS experiments (LHCC 95-30)*

o Engineering review group: LHC experiments installation (LHCC 95-31)*

o LDRB: Report on proposal P60 (LHCC 95-32)

o LERB: Report on the assessment of the RD12 effort (LHCC 95-33)

o LERB: Report on the assessment of the RD16 / FERMI effort (LHCC 95-34)

o LDRB: Report on RD40 (LHCC 95-35)

* Restricted circulation only.