31 March 2003
Minutes of the sixty-third meeting held on
Wednesday and Thursday, 26-27 March 2003
1. LHC Machine Magnet Technologies: Lucio Rossi
2. ATLAS Status Report: Peter Jenni
3. XVII Rencontres de Physique de la Vallée díAoste ó Highlights from a Winter Conference: Sandra Leone
4. Report from the Chamonix XII Workshop: Roger Bailey
Present: W. Bartel*, S. Bertolucci, K. Borras, M. Calvetti
(Chairman), R. Cashmore, A. Ceccucci, J. Dainton,
F. Ferroni, M. Hauschild, M. Jaffre, Y. Karyotakis, 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, V. Vuillemin* (representing D. Schlatter)
*) Part time
The report from the LHCb Comprehensive Review (LHCC
2003-006 / LHCC-G-025) was approved with the following modification: in point
4 (Outer Tracker), the last sentence of the first paragraph should be replaced
by `Good progress was reported on the ASDBLR and OTIS read-out electronics,
although potential problems resulting with the phasing-out of the DMILL
technology used for the former was noted.í
In addition, the LHCC will be reviewing the issue of the
required and available manpower for the core software in the experiments and
its relation to the LHC Grid Project (LCG). The review is being set up for the
summer and the panel will consist of members of the LHCC as well as external
experts. A report will be presented to the LHCC and to the October meetings of
the Resource Review Boards. In preparation for this review and to also provide
a status report on its activities, the LCG will be invited to report to the
Closed Session of the next LHCC.
The referees reported on the status of the DMILL production process. The firm ATMEL has announced that production in DMILL will be terminated in December 2003, with the last production orders to be taken in June 2003. Given that the 2002 production runs raised several worries due to the failure rate and low yield, the LHCC expressed its concern on the risk in procuring the total number of wafers, particular for the SCT ABCD, TRT ASDBLR and the chips for the LAr calorimeters, before the DMILL production is terminated. With the aid of the CERN Director for Collider Programmes, discussions are presently underway with ATMEL to achieve a viable solution. The impact on particularly the SCT and TRT schedule must be investigated.
The referees also gave an update on leaks in the MDT gas tubelets. The Barrel sites have decided to replace all brass tubelets with the new stainless steel tubes while the US End-cap groups have decided to equip all new chambers starting in January 2003. The latter groups will continue long-term tests until July 2003 and then decide whether to replace all the brass tubelets. The Protvino End-cap group uses home-made brass tubelets and no problems have been encountered so far. The above changes should not delay the completion of the chambers and the LHCC will continue monitoring the situation.
After an exposure equivalent to about 2 ATLAS years of running, no evidence of problems in the performance of the RPCs has been identified. Ageing tests will continue to a current equivalent to about 10 ATLAS years. Quality assurance of the RPC production has shown that about 25% of the chambers need to be re-worked due to faulty components resulting from both a wrong handling and assembly procedure. The LHCC noted that the quality control process during chamber mounting needs to be improved. As the re-assembly of an RPC requires less time than the assembly of a new chamber, the impact on the overall schedule can be limited.
The LHCC also heard a report on the TRT. The detector performance has been studied in detail with the new Xe/CO2/O2 gas mixture and no significant change has been observed with respect to that stated in the TDR. Moreover, no degradation of the active elements and detector components has been observed following an irradiation corresponding to 10 years of LHC operation. The cleaning mixture has been defined as Ar/CO2/CF4 (70%/26%/4%) and its use at the LHC is considered to be safe. Furthermore, accumulation of ozone does not affect the detector performance and studies with an ozone removal agent are underway. Studies of Si deposit effects are also underway but will be done in parallel with the TRT and gas system production. The LHCC also noted the concerns related to the TRT production schedule. In particular, the late availability of the front-end electronics as well as the shortage of manpower could delay the start of the TRT Barrel and End-cap integration. Moreover, the web-circuits are critical path items for the End-cap wheel assembly, as the inner End-cap A is already late by 4 months.
Finally, the referees reported on the Higher Level Trigger
/ DAQ. The final design review for the system is scheduled for March 2003 and
at which point a choice of the architecture will be made. The Higher Level
Trigger / DAQ TDR will be submitted to the LHCC at the end of June
The referees reported on the Tracker, concentrating on the procurement of the module components, the start-up of production and the schedule. The first mass production sensor batches have been received from Hamamatsu on schedule and are of excellent quality. Although still on schedule, the sensors from ST are not of similar excellent quality. A correlation has been found between scratches on the sensor surface and bad electrical behaviour leading to the need for a more stringent quality assurance procedure to be introduced at ST. Good progress was reported on the ASICS, pitch adapters, carbon-fibre frames and kapton insulators and the LHCC believes that delivery of these components with an acceptable quality will soon be a matter of course. Delays in the above components have resulted in an overall delay in the module production plan. As the production speed is still ramping-up, a reliable impact of the delays to the CMS installation plan cannot be given at this stage. However, it has become clear that the allocation of the 3-month contingency allocated in the production and assembly schedule has now been used up. Given the above issues, the referees will continue monitoring closely the Tracker progress.
Good progress was reported on the crystals for the ECAL. The delivery of 4 crystals per boule matches the expectations of the required crystal production rate. The crystal order for the End-cap calorimeter is currently being prepared.
The LHCC also heard a report on the Muon Project. Good progress was reported on the production of the DTs. The production rate has now been achieved at the three sites in Aachen, Legnaro (Padova) and CIEMAT. The LHCC requests further information on the progress chart for chambers at their final stage ó after being fully-equipped and tested and before their installation in CMS ó so that the Committee can track progress relative to the V33 CMS schedule. The first electronics Minicrate will be installed in May 2003, but concerns remain in the on-time delivery of components in the future. THE LHCC noted the RPC critical issues, particularly concerns about the barrel production being closely linked to installation. This is due to their insertion in the yoke as DT+RPC packages and the fact that the barrel RPCs are location-specific and have to be produced in the order required by the installation sequence. Difficulties in achieving steady production of the RPCs themselves is also a concern. Impressive progress was reported for the CSCs, with production considered to be on track. The LHCC considers it essential to review the complete status of the Muon project at the next meeting of the Committee.
The referees also reported on the CMS assembly and installation plan. Production of the magnet coil is progressing well but is on the critical path. The estimated delay can be reduced from 4 to 2 months by speeding up production of the coil. The full current underground magnet tests may have to be sacrificed in order to compensate the above two-month delay in the magnet coil. However, the LHCC wish to emphasise that the functional tests, cooldown, electrical checks and leak tests on the cold magnet, must be preserved. The delayed start of the Tracker production requires full exploitation of the production capacity to recover. Currently, the Trackerís 3-month contingency has been used up but the net delay still remains within the shadow of the additional 2-month coil delay. Following the revision of the electronics and assuming the anticipated rate of crystal production of 4 crystals per boule, the schedule to have a complete ECAL installed in April 2007 is considered by the LHCC to be realistic.
Finally, the LHCC noted that 90% of the V33 CMS schedule
milestones were met and also took note of the progress in the DCS project and
the studies for the lay-out of the Forward Region. The latter will be
presented in further detail to the May session of the Committee.
The referees reported on the status of the photodetector for the RICH. Concerns remain regarding the bump-bonding and correction of magnetic field distortions for the Hybrid Photo-Diode (HPD), while development of the read-out for the Multi-Anode Photomultiplier (MAPMT) has not yet been completed. Delays in tendering and ordering procedures were noted and add to the urgency in making a final decision. The LHCC re-iterated that focused studies of the HPD and MAPMT should continue with the aim of providing a final choice between the two options to be taken in September 2003. An intermediate review is planned for May 2003 and the LHCC will perform another in-depth review of the status at that time.
Good progress was reported on the re-optimisation studies for the LHCb detector. The production of simulated events is well underway. An alternative Level-1 trigger, to provide more flexibility and scalability, is being investigated and will be reviewed within LHCb in April 2003 with a report to the next session of the LHCC in May 2003. Depending on the changes, an update to the DAQ TDR may be requested by the LHCC. The LHCb Re-optimisation TDR remains on track to be submitted in September 2003.
The referees also reported on the schedules and milestones.
The Committee received a new document with updated milestones for the Muon
System and Inner Tracker following approval of the respective TDRs. The new list
will be henceforth used by the Committee to monitor and regulate future progress
of the LHCb project.
The LHCb Inner Tracker is estimated to cost 3.15 MCHF with the 75 man-years of manpower to be provided by the collaborating institutes deemed to be adequate. The cost estimates are based on quotes from industry and prototype work. No extra cost for assembly space, storage space or safety installations are needed, but additional costs for infrastructure may arise at a later stage. The cost is considered to be reasonable and fits into the overall cost of the LHCb experiment.
Replacing the RPC detector planes with MWPCs brings the cost
of the system from 10.83 MCHF to 10.98 MCHF. These cost estimates are based on
firm quotes from industry and prototype work. The institute manpower identified
for the RPCs can be transferred to the MWPC project and the cost of additional
manpower from PNPI St. Petersburg is included in the material budget. The
manpower is considered to be adequate. The cost is considered to be reasonable
and fits into the overall cost of the LHCb experiment.
A follow-up review to that in September 2002 of the installation of the ATLAS experiment in the underground experimental areas at Point 1 of the LHC was held on 12 March 2003. The Review Committee concentrated on the major concerns arising at the September 2002 Installation Review, which are reported in CERN/LHCC 2002-040. The Review Committee was impressed by the progress and work that has gone into the installation plan since the September 2002 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. This follow-up review has not identified any new major concerns, but a few items raised previously were not addressed, understandably, because of lack of time and some studies are clearly on-going. As a result of this present follow-up review, ATLAS is invited to consider a set of issues detailed in the report CERN/LHCC-2003-015 that should be addressed in greater detail in September 2003. In conclusion, the ATLAS technical coordination has the installation programme well in hand, but it remains a formidable task with a considerable risk of schedule delays. An on-going effort is required to ensure that there is a working detector at Point 1 ready for first collisions in Spring 2007.
Similarly, on 12 March 2003 the LHCC held a follow-up review to that in September 2002 of the installation of the CMS experiment in the underground experimental areas at Point 5 of the LHC. The Review Committee concentrated on the major concerns arising at the September 2002 Installation Review which are reported in CERN/LHCC 2002-028rev. The Review Committee was impressed by the progress and work that has gone into the installation plan since the September 2002 review. All of the concerns raised have been addressed and the Technical Co-ordination is making good progress within the available resources. There were no new major concerns in this follow-up review. As a result of this present follow-up review, CMS is invited to consider the set of issues given in the report CERN/LHCC-2003-016 that should be addressed in greater detail in September 2003. In conclusion, the CMS technical coordination has the installation programme well in hand, but delays in the arrival of certain sub-detectors may make it difficult to complete the installation and leave adequate time for global commissioning. Nonetheless, it is expected that CMS will have a working detector in time for first collisions in Spring 2007.
The first of the LHCC Installation Reviews of ALICE took place on 14 March 2003. The Review Committee was impressed by the amount of work which has already gone into the installation planning of the ALICE experiment and considers that a good over all scheme has already been developed, but also has to draw attention to the fact that a great deal of work remains to be done. Particular attention should be given by the core installation team to the co-ordination of the activities of the many different sub-detector teams of ALICE. The concerns of the Review Committee at this time are given in CERN-LHCC 2003-014. It is hoped that they will allow the Review Committee to follow up outstanding issues and to monitor future progress. The Technical Coordination was judged to have the installation of the ALICE detectors well in hand, but there is some risk of schedule delays as a result of the late completion and installation of some sub-detectors. In conclusion, the construction and installation has started well. More work is needed in particular on detector services and cabling and on the final stage DAQ commissioning, but there is every reason to believe that ALICE will have a useful, working detector ready for first collisions in Spring 2007.
Finally, the first of the LHCC Installation Reviews of LHCb took place on 13 March 2003. The Review Committee was impressed by the amount of work which has already gone into the installation plan of the LHCb experiment and considers that a good over all scheme has already been developed, but also has to draw attention to the fact that a great deal of work remains to be done. The concerns of the Review Committee at this time are given in CERN-LHCC 2003-017. They will allow the Review Committee to follow up outstanding issues and to monitor future progress.
The Technical Coordination was judged to have the
installation of the LHCb spectrometer well in hand, but there is some risk of
schedule delays as a result of the unavoidable interleaving with machine
installation. In conclusion, the construction and installation has started well.
More work is needed in particular on detector services and cabling and on the
final stage DAQ commissioning, but there is every reason to believe that LHCb
will have a complete and working detector ready for first collisions in Spring
The ALICE and LHCb dipole magnets are both on track and the reported costs are within the budget estimates. The LHCb dipole coils have been produced and delivered to CERN, while the steel plates for the yoke are in fabrication and delivery to CERN is on-going. Installation work at Point 8 has started with the magnet support structures being assembled. Manufacture of the coil for the ALICE dipole magnet has started and the yoke has been machined and assembled at Dubna.
Assembly of the CMS solenoid magnet is well underway on the surface at Point 5. The MAG is fully satisfied with progress on the yoke and end-caps of the magnet as well as with the cryogenic infrastructure. Good progress was also reported for the conductor since the continuing welding process works very well, thus allaying previous concerns. The LHCC noted the concerns related to the coil and in particular the delay in the mandrel production. The coil is thus 4 months late with respect to the V33 CMS schedule. The estimated delay can be reduced from 4 to 2 months by speeding up production of the coil. The full current underground magnet tests may have to be sacrificed in order to compensate the above two-month delay in the magnet coil. However, the LHCC wish to emphasise that the functional tests, cooldown, electrical checks and leak tests on the cold magnet, must be preserved. The MAG will re-appraise the situation in June.
The ATLAS magnet system consists of 4 large superconducting
magnets ó the Central Solenoid (CS), the Barrel Toroid (BT) and the two End Cap
Toroids (ECT). The CS coil, turret and chimney were delivered to CERN in 2001.
Good progress was reported on components of the BT, including the conductor,
coil, integration of the coil in its casing, vacuum vessel, integration into the
cryostat, and the cryo-ring. Concern remains with the delay in delivery of the
thermal shields, as this may result in a delay of the BT. The MAG considers the
schedule to be tight but feasible. Good progress was also reported on the
conductor, vacuum vessel and cold mass of the ECT. The MAG considers that the
ECT schedule is no longer critical as final assembly is expected to be on time.
Finally, the MAG noted the major effort put into containing costs and
Hardware tests at the PS start-up showed high unacceptable leakage currents in two bending magnets of the PS machine. Although spare magnets are available, and are currently being tested, a delay in the start-up of the PS and SPS is most probable, and will affect all CERN accelerator-related physics activities. Specifically for the LHC test beams, the delay may have consequences for the irradiation periods and ALICE tests in the PS East Hall and may result in a shorter overall SPS proton run. Discussions are on-going to limit the impact of the delays and a new PS and SPS machine schedule will be released shortly. The LHC experiments are requested to provide information to the SPS and PS Coordinator on their plans for using the LHC-type beams in 2003 as a change from their original request will have an impact on the new SPS schedule.
Finally, the SPS and PS Coordinator showed a possible
schedule for the SPS heavy-ion run, whereby agreement was reached between CMS
and ALICE to run together with NA45 and NA49. The schedule will be submitted for
approval to the Research Board in April.
Since the second of the Comprehensive Reviews in March 2002, the ALICE Collaboration has made very significant progress towards the realisation of an experimental set-up ready to record proton-proton and heavy-ion collisions at the LHC. The LHCC considers it reasonable to expect ALICE to be ready for first LHC operation in April 2007. In particular, most of the detector technologies to be used, together with the associated electronics, have successfully gone through the R&D phase and several major sub-systems, such as the Time Projection Chamber, dipole magnet and support structures, are in the production phase, while others, such as the Inner Tracking System, Transition Radiation Detector, Time-of-Flight detector and Dimuon Forward Spectrometer, are preparing to enter the series production phase. This is being done with the Collaboration adopting measures to control increases in the cost-to-completion. Moreover, the LHCC considers that ALICE has addressed satisfactorily the concerns of the LHCC at the second Comprehensive Review.
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 upcoming sessions of the LHCC prior to the next ALICE Comprehensive Review one year hence.
LHCC Secretariat: Janet Grant (Bldg. 14/4-022) Tel. 73424, janet.grant@CERN.CH