CERN/LHCC 96-24

LHCC 22

4 April, 1996

LARGE HADRON COLLIDER COMMITTEE

Minutes of the twenty-second meeting held on Thursday and Friday,
28-29 March 1996

CLOSED SESSION :

Present: J.Bernabeu, R.J.Cashmore, C.Dionisi, P.J.Dornan, J.Ellis*, J.Engelen, L.Foa, U.Goerlach, A.Golutvin, G.Goggi, D.Hartill, E.Iarocci (Chairman), P.Igo-Kemenes, C.Llewellyn Smith*, N.McCubbin, H.Montgomery, K.Nishikawa, K.Potter, A.Schopper, A.Schwarz, D.M.Sendall (Secretary), M.Spiro, M.Turala, H.Wenninger*, D.O.Williams, G.Wormser*.

*) Part time

Apologies: L.DiLella, L.R.Evans

1. The minutes of the twenty-first LHCC meeting (LHCC 96-11 / LHCC 21) were approved without amendment.

2. C.Llewellyn Smith summarised the status of negotiations with non-member states, and the possible implications for the timescale of the LHC project.

The LHCC is convinced of the advantage of building the machine in a single stage as soon as possible.

3. REPORT FROM THE ALICE REFEREES

The committee heard a report from the ALICE referees. The LHCC congratulates the ALICE collaboration on the substantial progress made on the major technical issues, as described in the technical proposal and discussed further with the referees.

The LHCC is pleased to learn that the collaboration will make every effort to submit the muon arm addendum to the technical proposal for the October 1996 meeting of the LHCC, which will allow the evaluation of the ALICE project as a whole.

4. SUSY WORKSHOP

J.Ellis reported on progress in planning the one-day supersymmetry workshop foreseen for 30 October 1996. Agreement had been reached on the choice of some particular regions of the parameter space to explore in more detail.

5. REPORTS FROM THE ATLAS AND CMS REFEREES

The committee heard reports from the ATLAS and CMS referees, including detailed reports on some subsystems. Good progress had been achieved on many fronts. Reviewing procedures for the Technical Design Reports were discussed. Both collaborations will submit a report to the LHCC Costs Review Group CORE in February 1997 so that CORE can report to the LHCC in May 1997.

6. EXPERIMENTAL AREAS AND LHC STUDIES

K.Potter reported on the definition of underground structures and surface buildings for the experimental areas. Offers for three civil engineering consultants have been adjudicated and contracts are in preparation. K.Potter also reported on encouraging results from the magnet string test, and on a recent workshop on LHC backgrounds.

7. REPORT FROM THE LHC-B REFEREES

The committee heard a report from the LHC-B referees covering recent activities of the collaboration.

8. FINAL REPORT FROM THE LDRB

Status reports have been submitted by RD18. RD26, RD28 and RD32.

Status Reports of approved projects presented at the open session

RD-18: New, fast and radiation hard scintillators for calorimetry at LHC (LHCC 96-19).

H.Tiecke gave an overview of the Crystal Clear project. A summary report on CeF3 work has been submitted for publication. Research in high light yield crystals has continued in collaboration with industry on medical and other applications. The main effort is on PbWO4. Production sites have delivered good quality crystals, but some problems were found including variations of light transmission, possibly correlated with radiation damage, and a slow component in the scintillation decay.

The LDRB supports continued efforts by the RD18 collaboration to understand these problems, in order to be ready for large scale production at the end of 1997.

The LDRB also supports continued collaboration with medical physicists on a new generation of medical imaging devices.

The LHCC endorsed these conclusions.

RD-26: Development of a large area advanced fast rich detector for particle identification at the Large Hadron Collider operated with heavy ions (LHCC 96-20).

H.Tiecke gave an overview of the work on developing CsI photocathodes for RICH applications. The collaboration has established the principle of operation with essentially full size cathode pad arrays, and have operated a system in a fixed-target heavy ion experiment. With the pad efficiency they now achieve, they believe that a detector in ALICE could provide the necessary particle identification efficiency.

The LDRB recognised the considerable progress made. However there is no complete understanding yet of a number of issues. Since this type of detector is very likely to be used in future experiments including ALICE, the LDRB recommends a continuation of RD26 for one more year to investigate the following points:

- construct reliably reproducible cathode pad arrays, in the light of differences in approach in different RD26 labs;

- discrepancies between measurements of pad efficiency using UV-source bench systems and using analysis of test beam data;

- short and long-term effects of UV irradiation;

- the role of pollutants in degradation of CsI performance;

- development of protective layers for CsI cathodes.

The LHCC endorsed these conclusions.

RD-28: Development of gas micro-strip chambers for high radiation-rate detection and tracking (LHCC 96-18).

RD28 submitted a final status report. The programme of generic R&D of Microstrip Gas Chambers, proposed in 1992, is now complete. As a consequence of co-ordinated work in many institutions, the major unknowns governing the basic operation and performance of MSGCs have been understood, and a baseline guide established in the design of detectors. Further R&D work will be needed within any experiment intending to use the technique.

The LDRB agree with the conclusions of the final RD28 report.

The LDRB and LHCC congratulated the collaboration on the results achieved.

RD-32: Development of a time projection chamber with high two track resolution capability for experiments at heavy ion colliders (LHCC 96-16).

RD32 submitted a final status report. They have completed a study of two- and three-component gas mixtures. For the TPC readout, conventional MWPCs are a viable solution: a new concept of ring cathode chambers looks promising, awaiting results from a prototype. New readout electronics has been developed and successfully tested.

The LDRB is confident that the necessary development will continue within the ALICE environment.

The LDRB and LHCC congratulated the collaboration on the results achieved.

H.Tiecke gave a summary of the situation of the remaining R&D projects. Those still active are RD8, RD18, RD26, RD39, RD42 and RD46.

On behalf of the LHCC, the Chairman warmly thanked H.Tiecke and the LDRB for their valuable work in reviewing the detector R&D projects.

9. REPORT FROM THE LCRB

A status report has been submitted by RD45.

Status Report of approved project presented at the open session

RD-45: A persistent object manager for HEP (LHCC 96-15).

R.Mount reported for the LCRB. The project has made excellent progress in identifying and applying solutions for object persistence for HEP based on standards and commercial products. The milestones set (as revised by the LCRB in November 1995) have been met.

The LCRB agrees with the program of future work outlined in the RD45 report, and has identified several activities as particularly important. The LCRB recommends continuation of RD45 for a further year with the following milestones:

- Analyse the impact of using an ODBMS for event data on the object model, the physical organisation of data, coding guidelines, and the use of third party class libraries.

- Investigate ways that ODBMS features for replication, schema evolution and object versions can be used to solve HEP data management problems.

- Evaluate the effectiveness of an ODBMS and MSS as the query and access method for physics analysis. The evaluation should include performance comparisons with PAW and Ntuples.

The LHCC endorsed these conclusions.

R.Mount also gave an outline of plans for the LHC computing workshop to be held in Padova on 11-13 June 1996.

10. OTHER BUSINESS

It was agreed that if possible the May meeting of the LHCC will be a one-day meeting: in that case it will take place on 30 May. The July meeting is provisionally cancelled, but may be reconvened if circumstances require.

11. DATES FOR 1996 MEETINGS

30-31 May (provisionally 30 May only)

(4-5 July meeting provisionally cancelled)

29-30 August

31 October - 1 November