LARGE HADRON COLLIDER COMMITTEE
Minutes of the sixty-sixth meeting held on
Wednesday and Thursday, 24-25 September 2003
1. LHCb Reports
- Introduction to the LHCb Reoptimisation and Trigger
- Technical Design Reports: T. Nakada
- Reoptimised RICH-1 Design: D. Websdale
- Trigger Tracker Design: M. Schmelling
- LHCb Trigger Overview: H. Dijkstra
- Level-0 Trigger Implementation: O. Callot
- Level-1 and High Level Trigger Implementation: N. Neufeld
- Physics Performance of the LHCb Detector: O. Schneider
- Overall Conclusions: T. Nakada
2. ATLAS High-Level Trigger, Data Acquisition and Control Technical Design Report: Livio Mapelli
3. LCG Status Report: Les Robertson
Present: S. Bertolucci, K. Borras, M. Calvetti (Chairman),
R. Cashmore, A. Ceccucci, F. Ferroni, M. Hauschild, M. Jaffre,
Y. Karyotakis, Y.-K. Kim, J. Knobloch, M. Mangano, J. Martin, J. May*, P. McBride, J. Panman*, K. Potter,
D. Schlatter, P. Seyboth, H. Tiecke, K. Tokushuku, E. Tsesmelis (Secretary), C. Vallée
Apologies: J.-J. Gomez-Cadenas
The minutes of the sixty-fifth LHCC meeting (LHCC 2003-028 / LHCC 65) and the report from the ATLAS Comprehensive Review (LHCC 2003-029 / G-041) were approved without modification.
The Director for Collider Programmes informed the LHCC on various issues concerning CERN in general and the LHC Project in particular.
He reported on the CERN Council meetings of September 2003. Finance Committee accepted all budget proposals submitted by the CERN Management for 2004. Good progress was reported on the LHC. Except for the works at Point 5, civil engineering for the LHC is complete. Production of collared-coils for the dipole magnets is ramping-up and two more dipole magnet test stations are coming online. It was acknowledged that CERN should take a European-wide role in discussions for a future linear collider, while at the same time continuing its R&D on CLIC in order to validate the technology.
The European Union approved the Enabling Grids for e-Science in Europe (EGEE) initiative, providing partial funding for operation of a general e-Science grid in Europe. EGEE will provide funding for 70 partners, the large majority of which have strong ties with the high energy physics community.
Finally, an open meeting is being organised for 2004 to discuss CERNís future fixed target programme.
3. REPORT FROM THE ALICE REFEREES
The LHCC heard a report from the ALICE referees, concentrating on the status of the sub-detectors and a report on the Addendum to the Photon Multiplicity Detector (PMD) Technical Design Report.
Good progress was reported on the ITS. A successful engineering run was reported for the SSD and module production is starting. Production for the front-end electronics is starting again for the SPD and sensor pre-production for the SDD is also commencing.
A new inner field cage for the TPC has been delivered and tested and part of the induced delay has been recovered. Good progress was reported on the other TPC sub-systems, including the resistor rod prototype, the front-end electronics and the laser system.
A successful test of the new ASIC front-end electronics for the TOF was reported. Construction of the RPC strips has been postponed by about 3 months to accommodate the new electronics. The LHCC does not consider the delay to be critical.
Progress was reported on the Dimuon Forward Spectrometer. The dipole magnet coils are complete and are being shipped to CERN. The steel plates for the yoke are also complete but their delivery from Russia has been delayed due to administrative difficulties. Discussions are continuing between CERN and the Russian authorities to proceed with the transport of the steel plates.
Good progress was reported on the PHOS, Trigger/DAQ, the V0 detector and the ZDC. Since the proposal to complete the TRD has not been approved in Japan, ALICE is proceeding with plans for a reduced coverage as described in the approved TRD Technical Design Report.
The Committee heard a report on the refereesí preliminary reactions to the Addendum to the PMD TDR (LHCC 2003-38 TDR 6 Add. 1). It was observed that the experimental beam pipe, which at the time of submission of the Technical Design Report in September 1999 (LHCC 1999-32 TDR 6), had a short beryllium section and a long stainless steel section, was a major source of background for the PMD. Moreover, since submission of the Technical Design Report, integration of the inner detectors, in particular the amount and routing of services, has been substantially refined. It was realized that structural components and services of the TPC and ITS introduce a large amount of material in front of the PMD. ALICE, therefore, decided to move the PMD to another position. The relocation of the PMD has resulted in modifications in the basic cell design and also changed the pseudorapidity coverage of the detector. The Committee is currently reviewing the Addendum to the PMD TDR. Following further questions and discussions, the referees will make a full report on the Addendum to the PMD TDR at the next meeting of the LHCC.
4. REPORT FROM THE ATLAS REFEREES
The LHCC heard a report from the ATLAS referees, concentrating on an update to the general status of the experiment, the LVL1 muon trigger beam tests, the measurement of the luminosity, the experimentís commissioning plan and a preliminary report on the HLT/DAQ/Controls Technical Design Report.
The referees reported on the ATLAS schedule and milestones. As was noted at the time of the ATLAS Comprehensive Review in July 2003, several systems no longer have any contingency in the schedule. The schedules of the Barrel Toroid Magnet, the SCT Endcap A, the TRT Endcap A, and the LAr Endcap A are considered to be critical, with the first two being the most serious. The first Barrel Toroid coil is scheduled to be tested in February 2004, namely a 2-month delay with respect to the ATLAS installation schedule. ATLAS plans to absorb the delay in Phase 2 of the installation schedule by bringing forward installation of the Tile and the LAr Barrel calorimeters.
The LHCC noted the successful beam tests of the TGC and RPC LVL1 muon trigger in the LHC-type structured beam at the SPS. Preliminary analysis of the data shows that the LVL1 muon trigger is performing as expected and the tests proved crucial in verifying that the LVL1 muon trigger will meet the ATLAS requirements. The electronics schedule remains tight, but the next ASIC submission is considered to be the final one.
The LHCC took note of the ATLAS plans for luminosity monitoring and calibration. The Committee, however, reiterated its concerns at the time of the July 2003 ATLAS Comprehensive Review, namely that the ideas for elastic scattering measurement have appeared late in the overall LHC programme and that no provisions either in the beampipe, beam optics, schedule or resources were contained in the baseline LHC plans.
The Committee also took note of the ATLAS commissioning plans. The work in progress on commissioning with cosmic radiation and beam-gas background was noted with interest but the Committee felt that as yet there is a stage missing in the commissioning process between detector installation and the commissioning described, notably the integration of the electronic systems/trigger/DAQ. ATLAS are requested to address this area in more detail at the next installation review in March 2004. In general preparation, installation and commissioning of electronics and the DAQ system need more work.
The Committee heard a report on the refereesí preliminary reactions to the ATLAS High-Level Trigger, DAQ and Controls Technical Design Report (LHCC 2003-022 TDR 16). The HLT/DAQ is broken down into four principal systems:
5. REPORT FROM THE LHCb REFEREES
The LHCC heard a report from the LHCb referees, concentrating on the preliminary reports on the LHCb Reoptimised Detector and Trigger Technical Design Reports and a general status report on the sub-detectors.
The Committee heard a report on the refereesí preliminary reactions to the LHCb Reoptimised Detector and Trigger Technical Design Reports (LHCC 2003-030 TDR 9 and LHCC 2003-031 TDR 10). The report describes the reoptimisation of the detector, which has been made to reduce the material budget and to improve the trigger performance. At the time of the Technical Proposal in 1998, the material budget up to RICH2 was 40% of X0 (10% of ?I). This increased to 60% and 20%, respectively by the time of the Outer Tracker TDR in September 2001. This led to a noticeable loss in the number of reconstructed B mesons from many-body final states. Moreover, the robustness and efficiency of the second trigger level (Level-1) could be significantly improved by not only using information from the VELO detector, as done in the Technical Proposal, but also adding pT information to tracks with large impact parameter. This can be achieved by associating the high-pT calorimeter clusters and muons obtained at Level-0 to the tracks found in the VELO. A complementary approach that is more efficient for hadrons is to get a rough pT estimate from the tracking. This requires the introduction of a magnetic field in the region of RICH1. The design of the RICH1 then had to be modified in order to protect its photon detectors from the field. Following further questions and discussions, the referees will make a full report on the Reoptimised Detector and Trigger TDRs at the next meeting of the LHCC.
Good progress was reported on the VELO, Outer Tracker, Calorimeters, Muon chambers, dipole magnet and RICH detectors. The Collaboration will review the choice between HPDs and MaPMTs for the RICH photon detector and provide their final decision to the LHCC in time for the November 2003 meeting of the Committee.
6. REPORT FROM THE LHC EXPERIMENT INSTALLATION REVIEWS
K. Potter presented a report from the LHC Experiment Installation Review meetings held on 8-10 September 2003 regarding the installation of the LHC experiments in their respective experimental areas. The Review Committees addressed the projected schedules and milestones, the required resources to carry-out the installation as well as identifying any potential risk of delays or over costs for the installation.
The second annual review of the installation of the ATLAS experiment in the experimental areas at Point 1 of the LHC was held on 10 September 2003. The Review Committee congratulated ATLAS on the impressive progress with their installations at Point 1 and the clarifications given on some of the concerns raised by the Committee in previous reviews. The Committee greatly appreciated the work put into the preparation of this second annual review by the ATLAS Technical Coordination team. The concerns of the Review Committee on this occasion are indicated in CERN/LHCC 2003-041 and these should be addressed in a follow-up review in March 2004. The Review Committee was impressed by the amount achieved since March of this year, but also has to draw attention to the fact that the installation will be long and difficult and a great deal of work remains to be done.
The over all planning has very few contingencies and this will make the handling of any delays, including the already known two month delay in the first BT cryostat very difficult. The introduction of multi-shift working can be used to cope with delays, but will often require additional resources and reorganisation of the funding. Introducing second shift working may also clash with the installation of services and the commissioning of detectors. Nevertheless it remains true that as far as it was possible to determine the present funding arrangements are commensurate with the plans as described.
The Technical Coordination was judged to have this difficult task well in hand, but there is a considerable risk of schedule delays and an extraordinary effort is still required to ensure that ATLAS has a working detector ready for first LHC beams in April 2007.
Similarly, on 9 September 2003 the second annual review of the installation of the CMS experiment in the experimental areas at Point 5 of the LHC was held. The Review Committee congratulated CMS on their excellent presentations and team spirit and was impressed with the well thought out approach to the installation of the CMS detector at Point 5. The Committee greatly appreciated the work put into the preparation of this second annual review by the CMS Technical Coordination team. The CMS installation schedule is considered to be reasonable, but the Review Committee has a few concerns, as detailed in CERN/LHCC 2003-042, which should be addressed in a follow-up review in March 2004.
The installation still has a long way to go and much work remains to be done. The main concern remains the timely completion and delivery of the sub-detectors. The installation planning is realistic, but contains no contingency for the late arrival of sub-detectors and the conclusion must be that even slightly late deliveries will result in an incomplete detector in April 2007.
In conclusion, the construction and installation of the CMS experiment is progressing well and there is every reason to believe that CMS will have a working detector ready for first collisions in April 2007, but not necessarily with every detector module installed.
On 8 September 2003 a follow-up review to that in March 2003 of the installation of the ALICE experiment in the experimental areas at Point 2 of the LHC was held. The Review Committee congratulated ALICE on their useful and detailed response to the concerns of the March 2003 review and also on their progress with the organisation and planning of the installation of the ALICE detector. The Committee greatly appreciated the work put into the preparation of this follow-up review by the ALICE Technical Coordination.
The Review Committee was impressed by the progress and work which has gone into the installation plan since the March 2003 review. Many of the concerns raised have been addressed and the position of the Technical Co-ordination clarified. The installation team is clearly in place and working together as a team, making good use of available resources from collaborating institutes.
This follow-up review has not identified any new major concerns, but a few items raised previously were not addressed and certain studies are clearly on-going. It was announced that they would be treated in more detail next time. As a result of this present follow-up review ALICE is invited to consider certain issues detailed in CERN/LHCC 2003-040, which should be addressed in greater detail in March 2004.
The ALICE technical coordination has the installation programme well in hand, but the loss of all contingency, even in phase 1 is a concern. Nevertheless a working detector can be confidently expected at Point 2 ready for first collisions in Spring 2007.
Finally, on 8 September 2003 a follow-up review to that in March 2003 of the installation of the LHCb experiment in the experimental areas at Point 8 of the LHC was held. The Review Committee congratulated LHCb on their useful and detailed response to the concerns of the March 2003 review and also on their progress with the organisation and planning of the installation of the LHCb detector. The Committee greatly appreciated the work put into the preparation of this follow-up review by the LHCb Technical Coordination.
The Review Committee was impressed by the progress and work which has gone into the installation plan since the March 2003 review. Most of the concerns raised have been addressed and the Technical Co-ordination is making good progress.
There were no new major concerns in this follow-up review but LHCb is invited to consider certain issues detailed in CERN/LHCC 2003-043 which should be addressed in greater detail in March 2004.
The LHCb Technical Coordination has the installation programme well in hand and it can be confidently predicted that they will have a working detector in time for first collisions in Spring 2007.
Finally, it was noted that all experiments need to continue their considerations on safety practices and the organisation of safety within the collaborations. This should be done together with the involvement of TIS Division.
7. REPORT FROM THE REVIEW OF COMPUTING RESOURCES FOR THE LHC EXPERIMENTS
On 2-5 September 2003 the LHCC held a review of the software manpower requirements of the four LHC experiments. The Review Committee concentrated on the details of their planned software activities and work packages and examined how software development has been organized in each experiment. The leaders of the software effort in each of the experiments made presentations to the Committee that were primarily focused on the effort required for core software activities, simulations, high-level trigger infrastructure and for the experimentsí interaction with the LCG projects. They also described the level of effort required for the development of sub-detector application software and algorithms.
The Committee was charged with the task of examining the
required and available manpower for the core software and sub-detector software
inside the experiments and explore their relation to the LCG Project in order to
evaluate whether the experiments are putting the proper effort into these
computing tasks. The LCG projects were not reviewed per se but
participated in the review in order to provide a link to the experiments in
terms of the overall required manpower and to provide details of the
deliverables to the experiments. Moreover, the review was not a technical
evaluation of the computing but remained focused on issues related to manpower
resources, the scope of the work and the progress evaluation mechanisms.
The conclusions and concerns of the Review Committee are given below.
8. TEST BEAMS
The SPS and PS Coordinator reported on the test beams.
He gave a status report on the SPS, reporting on problems with the accelerator over the summer period. Water leaks in magnets and several vacuum leaks in the TT20 transfer line to the North Area resulted in lengthy stops to physics and to a drop in the overall SPS beam availability for 2003 to about 65% from the 87% in 2002. He reported on the successful TT40 extraction machine development, which provided a first test of the SPS beam extraction into the new TT40 extraction line for the LHC (and CNGS) and on the successful SPS machine development with LHC-type bunched-beam with the 75 ns bunch-spacing.
The additional SPS beam period with the 25 ns beam structure requested by ATLAS was highly successful. The conditions provided by the accelerator complex were excellent and the LHCC congratulates the PS and SPS crews and the experiment teams for recording useful data.
Finally, he presented the draft SPS and PS Complex machine schedules for 2004. The SPS proton run is scheduled for the period 10 May to 29 October and includes two 1-week periods of 25 ns running in early June and early October while the PS East Hall will run for a 24-week period starting on 3 May and ending 1 November. The end of physics in 2004 also sees the end of particle beams to the West Area. The GIF will, however, continue to run with source only. Finally, no SPS and PS beams will be available in 2005, and the accelerator complex will re-start in spring 2006.
9. CMS COMPREHENSIVE REVIEW
Since the third of the CMS Comprehensive Reviews in October 2002, the CMS Collaboration has made very significant progress towards the realisation of an experimental set-up ready for LHC operation in April 2007.
It is realistic to expect CMS to install an initial working detector suitable for LHC operation starting in April 2007, although the completion of the detector installation can be foreseen beyond this date. The LHCC considers that the CMS schedule to achieve this is challenging. In particular, the Committee expressed its concern on the outstanding critical items related to the timely completion of the ECAL and Tracker detectors. The LHCC noted that additional resources, both in terms of money and manpower, would aid in accelerating the current CMS schedule, and thereby would ensure a timely completion of the initial detector in 2007.
In the event that additional funding is not available to ensure completion of CMS in 2007 as described in the Technical Design Reports, the installation of some components of the Tracker, HCAL, Muon System, and TRIDAS will be deferred in a staging plan which has been prepared. The proposed staging plan for the experiment is aimed at having as small as possible an adverse impact on the Higgs and SUSY sensitivity at a luminosity of order 1033 cm-2 s-1. In these circumstances, the installation of staged components, in a shutdown after the completion of the low luminosity running, while requiring additional resources, would complete the CMS detector as described in the approved Technical Design Reports for high luminosity running.
The third annual LHCC Comprehensive Review of CMS took place on 22-23 September 2003. The LHCC referees addressed the following areas: Tracker, Electromagnetic and Hadronic Calorimetry, Muon Spectrometer, Trigger/DAQ, Computing/Software, and the topics of Management, Technical Coordination, Integration, Schedules and Costs.
The conclusions and concerns of the LHCC are given below. They will allow the Committee to follow up outstanding issues and to monitor future progress of this project in forthcoming sessions of the LHCC prior to the next CMS Comprehensive Review one year hence.
The LHCC took note of the Letter of Intent for the measurement of photons and neutral pions in the very forward region of the LHC. The LHCC will evaluate the document and certain members of the Committee have been requested to study the interfaces to the LHC machine and the physics interest of the measurement.
11. DATES FOR LHCC MEETINGS
Dates for 2003:
Dates for 2004:
30 June - 1 July
The LHCC received the following documents
* Restricted circulation