25 th ALICE RRB l Collaboration News l
25 th ALICE RRB l Collaboration News l ALICE Status ð Hardware status ð Commissioning activities ð Planning 12 Nov 2008 25 th ALICE RRB J. Schukraft CERN-RRB-2008 -115
Collaboration News l New Institutes ð Houston (USA) EMCAL, Computing l Institutes leaving ð BARC Mumbai (India) leaving ALICE µ associate member, completed its technical contribution to the PMD electronics l Ongoing discussions ð Comsats, Pinstec (Pakistan) Physics, computing ð l Elections/Nominations ð Spokesperson: JS re-elected 1. 3. 2009 until end 2010 µ Deputy Spokesperson, P. Kuijer (NIKHEF/Utrecht), 2010) ð Resource Coordinator: C. Decosse (CERN) 2 years (2009(J. de Groot decided to step down end 2008) 2 µ Special thanks to J. de Groot, first (and only) RC since 1996 12/11/2008 25 th RRB J. Schukraft
Funding l UK : Continued support from STFC for ALICE ð ALICE & STAR groups merged, will apply at next funding round for Nuclear Physics grant. l CERN: ‘White paper money’ ð CERN share of 2. 5 MCHF has been agreed to complete the ALICE detector restore full DAQ capacity, complete TRD/EMCAL services & infrastructure, µ repay loan to CF for ZDC vacuum chamber ð additional contributions received (or requested) from other FA µ MCHF TRD EMCal 10. 0 Estimated CORE equivalent, agreed by US-DOE December 2007. EMCal 1. 6 1 MEUR, France, IN 2 P 3, agreed EMCal 1. 6 1 MEUR, Italy, INFN, 2008 fraction agreed C/F, C&I 0. 2 Extra contribution (. 249 MCHF, paid 2007) from France IN 2 P 3 PHOS 3 8. 0 5 MEUR, contribution from Germany, agreed early 2006 15. 0 Extra funds for two PHOS modules requested (Russia); 610 k. CHF allocated in 2008 to date 12/11/2008 25 th RRB J. Schukraft
ALICE Detector Installation mid 2008 Complete: ITS, TPC, TOF, HMPID, FMD, T 0, V 0, ZDC, Muon arm, Acorde ALICE Status Partial installation: 1/5 PHOS 4/18 TRD 9/48 PMD 0/6 EMCAL ~ 40% DAQ/HLT 4 Installation targets met by mid 2008 12/11/2008 25 th RRB J. Schukraft
24 April: Insertion of final TOF super module 5 12/11/2008 25 th RRB J. Schukraft
6 Installation of final muon chamber 12/11/2008 25 RRB J. Schukraft th
7 Installation 1 st PHOS module 12/11/2008 25 RRB J. Schukraft th
8 Formal end of ALICE installation July 2008 12/11/2008 25 th RRB J. Schukraft
Data Taking & Commissioning l Comissioning runs (24/7) ð Cosmics I (2 weeks, Dec 2007) µ local (individual detectors) and start of global (several detectors) commissioning ð Cosmics II (3 weeks, Febr/Mar 2008) µ local/global commissioning, first few days of alignment ‘test’ run, magnet commissioning µ TPC was turned off after ~ 1 week (Drift HV instability, now understood & corrected) ð Cosmics III (since 5 May 2008 continuous operation 24/7) µ global commissioning, calibration & alignment production runs l Injection tests ð TI 2 dump in June , injection tests August, first circulating beam September ð observed very high particle fluxes during dumps and even during injection through ALICE µ 10’s to 1000’s of particles/cm 2 with beam screens in LHC and/or TI 2 µ decided to switch off all sensitive detectors during injection > 6 months 24/7 running SPD, V 0 always on (trigger), ~ 6700 shifts (~ 30 MY) SSD, SDD, FMD, T 0, HMPID, muon trigger occasionally + (beam was useful only for a subset of detectors !) 2800 ‘on call’ 9 12/11/2008 25 th RRB J. Schukraft
Injection tests SPD hits versus bunch intensity (beam through ALICE) FMD event display (1 bunch through ALICE, > 100 000 hits) FMD hits versus SPD hits (beam through ALICE) 10 SPD/SSD, Sunday, 15. 6 Dump on TED 12/11/2008 25 th RRB J. Schukraft
First beam 10 th September SPD hits on 10. 9. 2008, shortly after 9 am V 0 hits on 10. 9. 2008, shortly after 9 am 11 12/11/2008 25 th RRB J. Schukraft
Luminosity monitor (V 0) Double turn, beam 1 back at point 2 ! Single turn 12 12/11/2008 25 th RRB J. Schukraft
Beam pick-up T 0 SPD V 0 Auto-correlation for SPD trigger, with multi-turn correlations (3564 bunch crossings) Trigger timing (before alignment) versus bunch number single shot for SPD, V 0, beam-pickup BPTX, T 0 triggers 13 12/11/2008 25 th RRB J. Schukraft
First interactions 12 th September ITS tracks on 12. 9. 2008 7 reconstructed tracks, common vertex 14 Circulating beam 2: stray particle causing an interaction in the ITS 12/11/2008 25 th RRB J. Schukraft
TPC Commissioning l TPC up and running since end 2007 ð chamber+FC, gas system, cooling, FEE, Laser, DCS, DAQ, HLT, … µ noise reduction: modify PS (some occasional excess noise remains in outer parts) µ replaced several faulty electronics components (FEE, RCU, . . ) µ some IROC decoupling capacitors show leakage after months of operation already several replaced, currently 2 ‘weak’ left + 2 IROCs not operational µ difficult or no access to parts of the TPC => modify cabling during shutdown 15 TDR: s ~ 1 measured: 0. 7 -0. 8 12/11/2008 25 th RRB J. Schukraft
TPC Calibration Krypton Gain Calibration l Gain, drift velocity, Ex. B, alignment, … ð Laser, Cosmics, Krypton, drift velocity monitor, gas composition, T/P sensors. . Ex. B scan (Laser tracks) Krypton Calibration Drift velocity from Laser (~ 2 x 10 -4) chamber gain variation (s ~ 8%) 16 12/11/2008 25 th RRB J. Schukraft
TPC Performance l First preliminary results from cosmics ð d. E/dx resolution (PPR goal: ~ 5. 5%) µ < 6% ð pt resolution (PPR goal: ~ 5% @ 10 Ge. V) µ ~ 10% @ 10 Ge. V w/o calibration Momentum Resolution (uncalibrated) Particle Identification 17 12/11/2008 25 th RRB J. Schukraft
Silicon: ITS & FMD status l all silicon detectors fully commissioned (Det. , DAQ, DCS, cooling, . . ) ð pixel trigger worked ‘out of the box’ and was heavily used ð individual bad/noisy channels ~ within specs (<0. 15% SPD, FMD, 1. 5% SSD, 3% SDD) ð lost some modules/half-ladders (tracking is sufficiently redundant, so physics impact is minor) (ITS detectors could only be fully tested after cabling on miniframe, i. e. w/o access) µ SPD: 12. 5% half-staves (2 connection, 13 insufficient cooling flow) plan to improve flow regulation for individual circuits next WS µ SDD: 5% modules (few can be recovered during shutdown) µ SSD: 3. 8% modules, 9% half-ladders mostly Sintef ladders which developed excessive bias current (8/22) FMD: S/N ~ 30 FMD 3 -o SSD FMD 2 -o SSD: S/N ~ 40 FMD 1 -i 18 FMD 2 -i FMD 3 -i 12/11/2008 25 th RRB J. Schukraft
ALICE Inner Tracking System: Alignment with Cosmics Silicon Pixel Detector (SPD): • ~10 M channels • 240 sensitive vol. (60 ladders) Silicon Drift Detector (SDD): • ~133 k channels • 260 sensitive vol. (36 ladders) Silicon Strip Detector (SSD): • ~2. 6 M channels • 1698 sensitive vol. (72 ladders) ITS total: 2. 2 k alignable sensitive volumes 13 k degrees of freedom l Alignment using tracks and Millepede program in a hierarchical approach l ~50 k cosmic for alignment collected since end of May (~0. 1 Hz), using Pixel trigger ITS Event display 19 Distribution of clusters in the 6 layers
ALICE Inner Tracking System: Alignment with Cosmics l Preliminary results for SPD (Pixels, ~ 80% prel. aligned): Track-to-track (top vs bottom) distance in transv. plane before alignment after alignment = 55 m (vs 40 m in simulation without misalignment) Track-to-“extra clusters” distance in transv. plane (sensor overlap) before alignment after alignment = 21 m (vs 15 m in simul. without misalignment) l Residual misalignment < 10 m (detector resolution = 12 m in r ) l SSD & SDD, as well as ITS/TPC alignment has started (smaller coverage) 20
Other Detectors l TOF: 2/3 fully commissioned (3 finishing gas tests, several missing DC-DC converters) ð TOF trigger works very well (noise factor 2 better than in tests) l TRD: 4 SM’s installed (2 final ones), noise and L 1 trigger ok l HMPID: fully commissioned, noise at specs l PHOS: 1 module fully commissioned, trigger com. ongoing ð occasional noise pickup (depends on the day. . ) l Muon tracking: ~ 70% commissioned, noise problem cured in all but station 3 l Muon trigger, V 0, T 0, ACORDE, ZDC: all up and running HMPID cosmic event TRD cosmic (no calib/slewing, offset correction etc. . ) Oct 08 Jul 08 TOF raw spectra (no calib/slewing, offset correction etc. . ) 21 12/11/2008 25 th RRB J. Schukraft
Online l Continuous online operation since March (24/7) ð DAQ: 40% HW installed, stable operation up to 500 MB/s transfer, data taking > 3 k. Hz µ complete HW for 2009 ð DCS/ECS: all essential functionality operational, continuous improvement in functionality µ some problems encountered with scalability (mostly resolved) ð CTP: some problems with spurious triggers resolved, running well ð HLT: 500 CPU’s, very successful operation (online reconstruction, data reduction) µ complete HW in 2009 Aggregated cumulative time in the global partition 22 12/11/2008 25 th RRB J. Schukraft
DAQ: Global Partitions Number of detectors in the global partition Now also runs with large number of detectors run stable over hours with realistic trigger sequences ! (Useful cosmic data taking done for subsets of detectors working with different triggers) 12/11/2008 25 RRB J. Schukraft 23 th
Offline & Physics ‘commissioning’ l Offline ð exercise data transfer to T 0/T 1, prompt reconstruction, prompt calibration, data Q/A l Concentrating on early physics at 900 Ge. V and 10 Te. V ð global event features, pt spectra, particle rations, baryon transport, …. ð detailed trigger & data taking scenario elaborated ð fast calibration/alignment/reconstruction prepared ð daily meetings of ‘first physics task force’ to exercising analysis until mid Sept. 24 12/11/2008 25 th RRB J. Schukraft
Computing l Computing Resources (updated after CRSG review) ð ALICE deficit in 2009 : ~ 25 CPU% , 60% Disk (error found by CRSG), 50% Tape µ ‘optimistic running scenario’ 107 s, but ALICE pp data depends much less on it ! µ need 109 pp MB events/year, i. e. 107 s@100 Hz or 106 s@1000 Hz l addressing the shortfall 25 ð adding resources: partially successful and ongoing µ in discussion with a number of specific partners ðredistribution of existing resources between experiments (integral LHC resources much more adequate than differential distribution) µ CRSG: ‘A very limited degree of redistribution of resources may be advisable in 2009’ ð ‘living with less’: scenarios & physics impact under discussion with LHCC µ a modest shortfall may be accommodated with a modest loss of physics 24/10/2007 … 23 rd 12/11/2008 25 RRB J. Schukraft th
Planning l Until 12 October ð continue cosmic running & consolidation of online software l Medium term (until LHC restart in 2009) ð ‘shutdown mode’, start with activities planned for winter shutdown µ re-arrange cabling on mini-frame (ITS, TPC) to allow better access to electronics major activity, requiring > 4 months of work both underground & surface µ detector consolidation TPC capacitors; recover some ITS modules, improve SPD cooling, … µ detector installation (TRD, PHOS, PMD, EMCAL), … 3 PHOS, 6 -8 TRD modules, 2 EMCAL modules, complete PMD l Long term: complete detector ð PMD (2008), DAQ/HLT(2009), TRD (2009), PHOS (2010/11), EMCAL (2010/11) 26 12/11/2008 25 th RRB J. Schukraft
Summary l Installation: ð met all installation goals by mid 2008 l Commissioning and initial calibration/alignment ð went rather well, sometimes even better than expected (e. g. TPC, SPD alignment + trigger) ð some (mostly minor) hickups / problems (noise, lost channels) / bug fixing ð to be improved: µ access to TPC for repairs/FEE exchanges µ cooling flow of SPD l Detector performance ð better – within - very close to specs (at least as far as could be verified with cosmics) After > 15 years of designing & constructing ALICE we do have a working experiment ready for physics. Thanks to all the Funding Agencies who have made this possible with their strong support over 1½ decades ! 27 12/11/2008 25 th RRB J. Schukraft
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