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25 th ALICE RRB

25 th ALICE RRB. Collaboration News ALICE Status Hardware status Commissioning activities Planning. CERN-RRB-2008-115. Collaboration News. New Institutes Houston ( USA ) EMCAL, Computing Institutes leaving BARC Mumbai (India) leaving ALICE

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25 th ALICE RRB

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  1. 25th ALICE RRB Collaboration News ALICE Status Hardware status Commissioning activities Planning CERN-RRB-2008-115 25th ALICE RRB J. Schukraft

  2. Collaboration News • New Institutes • Houston (USA) EMCAL, Computing • Institutes leaving • BARC Mumbai (India) leaving ALICE • associate member, completed its technical contribution to the PMD electronics • Ongoing discussions • Comsats, Pinstec (Pakistan) Physics, computing • Elections/Nominations • Spokesperson: JSre-elected 1.3.2009 until end 2010 • Deputy Spokesperson, P. Kuijer (NIKHEF/Utrecht), 2 years (2009-2010) • Resource Coordinator: C. Decosse (CERN) (J. de Groot decided to step down end 2008) • Special thanks to J. de Groot, first (and only) RC since 1996 • Run Coordinator: J. Rak (Jyvaskyula) 1 year (2009)

  3. Funding • UK : Continued supportfrom STFC for ALICE • ALICE & STAR groups merged, will apply at next funding round for Nuclear Physics grant. • CERN: ‘White paper money’ • CERN share of 2.5 MCHF has been agreed to complete the ALICE detector • restore full DAQ capacity, complete TRD/EMCAL services & infrastructure, • repay loan to CF for ZDC vacuum chamber • additional contributions received (or requested) from other FA

  4. ALICE Detector Installation mid 2008 Complete: ITS, TPC, TOF, HMPID, FMD, T0, V0, ZDC, Muon arm, Acorde Partial installation: 1/5 PHOS 4/18 TRD 9/48 PMD 0/6 EMCAL ~ 40% DAQ/HLT ALICE Status Installation targets met by mid 2008

  5. 24 April: Insertion of final TOF super module

  6. Installation of final muon chamber

  7. Installation 1st PHOS module

  8. Formal end of ALICE installation July 2008

  9. Data Taking & Commissioning • Comissioning runs (24/7) • Cosmics I (2 weeks, Dec 2007) • local (individual detectors) and start of global (several detectors) commissioning • Cosmics II (3 weeks, Febr/Mar 2008) • local/global commissioning, first few days of alignment ‘test’ run, magnet commissioning • TPC was turned off after ~ 1 week (Drift HV instability, now understood & corrected) • Cosmics III (since 5 May 2008 continuous operation 24/7) • global commissioning, calibration & alignment production runs • Injection tests • TI2 dump in June , injection tests August, first circulating beam September • observed very high particle fluxes during dumps and even during injection through ALICE • 10’s to 1000’s of particles/cm2 with beam screens in LHC and/or TI2 • decided to switch off all sensitive detectors during injection • SPD, V0 always on (trigger), • SSD, SDD, FMD, T0, HMPID, muon trigger occasionally • (beam was useful only for a subset of detectors !) > 6 months 24/7 running ~ 6700 shifts (~ 30 MY) + 2800 ‘on call’

  10. 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) SPD/SSD, Sunday, 15.6 Dump on TED

  11. First beam 10th September SPD hits on 10.9.2008, shortly after 9 am V0 hits on 10.9.2008, shortly after 9 am

  12. Luminosity monitor (V0) Double turn, beam 1 back at point 2 ! Single turn

  13. Beam pick-up T0 SPD V0 Auto-correlation for SPD trigger, with multi-turn correlations (3564 bunch crossings) Trigger timing (before alignment) versus bunch number single shot for SPD, V0, beam-pickup BPTX, T0 triggers

  14. First interactions 12th September Circulating beam 2: stray particle causing an interaction in the ITS ITS tracks on 12.9.2008 7 reconstructed tracks, common vertex

  15. TPC Commissioning • TPC up and running since end 2007 • chamber+FC, gas system, cooling, FEE, Laser, DCS, DAQ, HLT,… • noise reduction: modify PS (some occasional excess noise remains in outer parts) • replaced several faulty electronics components (FEE, RCU, ..) • some IROC decoupling capacitors show leakage after months of operation • already several replaced, currently 2 ‘weak’ left + 2 IROCs not operational • difficult or no access to parts of the TPC => modify cabling during shutdown TDR: s ~ 1 measured: 0.7-0.8

  16. ExB scan (Laser tracks) Drift velocity from Laser (~ 2x10-4) TPC Calibration Krypton Gain Calibration • Gain, drift velocity, ExB, alignment,… • Laser, Cosmics, Krypton, drift velocity monitor, gas composition, T/P sensors .. Krypton Calibration chamber gain variation (s ~ 8%)

  17. Momentum Resolution (uncalibrated) TPC Performance • First preliminary results from cosmics • dE/dx resolution (PPR goal: ~ 5.5%) • < 6% • pt resolution (PPR goal: ~ 5% @ 10 GeV) • ~ 10% @ 10 GeV w/o calibration Particle Identification

  18. Silicon: ITS & FMD status • all silicon detectors fully commissioned (Det.,DAQ, DCS, cooling, ..) • pixel trigger worked ‘out of the box’ and was heavily used • individual bad/noisy channels ~ within specs (<0.15% SPD, FMD, 1.5% SSD, 3% SDD) • 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) • SPD: 12.5% half-staves (2 connection, 13 insufficient cooling flow) • plan to improve flow regulation for individual circuits next WS • SDD: 5% modules (few can be recovered during shutdown) • SSD: 3.8% modules, 9% half-ladders • mostly Sintef ladders which developed excessive bias current (8/22) FMD: S/N ~ 30 FMD3-o SSD SSD: S/N ~ 40 FMD2-o FMD 1-i FMD 2-i FMD 3-i

  19. ALICE Inner Tracking System: Alignment with Cosmics • Alignment using tracks and Millepede program in a hierarchical approach • ~50k cosmic  for alignment collected since end of May (~0.1 Hz), using Pixel trigger Silicon Pixel Detector (SPD): • ~10M channels • 240 sensitive vol. (60 ladders)‏ Silicon Drift Detector (SDD): • ~133k channels • 260 sensitive vol. (36 ladders)‏ Silicon Strip Detector (SSD): • ~2.6M channels • 1698 sensitive vol. (72 ladders)‏ ITS total: 2.2k alignable sensitive volumes  13k degrees of freedom ITS Event display Distribution ofclustersin the 6 layers

  20. ALICE Inner Tracking System: Alignment with Cosmics • Preliminary results for SPD (Pixels, ~ 80% prel. aligned): • Residual misalignment < 10 m (detector resolution = 12 m in r ) • SSD & SDD, as well as ITS/TPC alignment has started (smaller coverage) Track-to-“extra clusters” distance in transv. plane (sensor overlap) Track-to-track (top vs bottom) distance in transv. plane before alignment before alignment after alignment after alignment = 55 m (vs 40 m in simulation without misalignment)‏ = 21 m (vs 15 m in simul. without misalignment)‏

  21. Oct 08 Other Detectors • TOF: 2/3 fully commissioned (3 finishing gas tests, several missing DC-DC converters) • TOF trigger works very well (noise factor 2 better than in tests) • TRD: 4 SM’s installed (2 final ones), noise and L1 trigger ok • HMPID: fully commissioned, noise at specs • PHOS: 1 module fully commissioned, trigger com. ongoing • occasional noise pickup (depends on the day..) • Muon tracking: ~ 70% commissioned, noise problem cured in all but station 3 • Muon trigger, V0, T0, ACORDE, ZDC: all up and running TRD cosmic HMPID cosmic event (no calib/slewing, offset correction etc..) Jul 08 TOF raw spectra (no calib/slewing, offset correction etc..)

  22. Online • Continuous online operation since March (24/7) • DAQ: 40% HW installed, stable operation up to 500 MB/s transfer, data taking > 3 kHz • complete HW for 2009 • DCS/ECS: all essential functionality operational, continuous improvement in functionality • some problems encountered with scalability (mostly resolved) • CTP: some problems with spurious triggers resolved, running well • HLT: 500 CPU’s, very successful operation (online reconstruction, data reduction) • complete HW in 2009 Aggregated cumulative time in the global partition

  23. 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)

  24. Offline & Physics ‘commissioning’ • Offline • exercise data transfer to T0/T1, prompt reconstruction, prompt calibration, data Q/A • Concentrating on early physics at 900 GeV and 10 TeV • global event features, pt spectra, particle rations, baryon transport, …. • detailed trigger & data taking scenario elaborated • fast calibration/alignment/reconstruction prepared • daily meetings of ‘first physics task force’ to exercising analysis until mid Sept.

  25. Computing • Computing Resources (updated after CRSG review) • ALICE deficit in 2009 : ~ 25 CPU% , 60% Disk (error found by CRSG), 50% Tape • ‘optimistic running scenario’ 107 s, but ALICE pp data depends much less on it ! • need 109 pp MB events/year, i.e. 107s@100 Hz or 106s@1000 Hz • addressing the shortfall • adding resources: partially successful and ongoing • in discussion with a number of specific partners • redistribution of existing resources between experiments (integral LHC resources much more adequate than differential distribution) • CRSG: ‘A very limited degree of redistribution of resources may be advisable in 2009’ • ‘living with less’: scenarios & physics impact under discussion with LHCC • a modest shortfall may be accommodated with a modest loss of physics … 24/10/2007 23rd RRB J. Schukraft 25

  26. Planning • Until 12 October • continue cosmic running & consolidation of online software • Medium term (until LHC restart in 2009) • ‘shutdown mode’, start with activities planned for winter shutdown • re-arrange cabling on mini-frame (ITS,TPC) to allow better access to electronics major activity, requiring > 4 months of work both underground & surface • detector consolidation TPC capacitors; recover some ITS modules, improve SPD cooling, … • detector installation (TRD, PHOS, PMD, EMCAL), … • 3 PHOS, 6-8 TRD modules, 2 EMCAL modules, complete PMD • Long term: complete detector • PMD (2008), DAQ/HLT(2009),TRD (2009), PHOS (2010/11), EMCAL (2010/11)

  27. Summary • Installation: • met all installation goals by mid 2008 • Commissioning and initial calibration/alignment • went rather well, sometimes even better than expected (e.g. TPC, SPD alignment + trigger) • some (mostly minor) hickups / problems (noise, lost channels) / bug fixing • to be improved: • access to TPC for repairs/FEE exchanges • cooling flow of SPD • Detector performance • 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 !

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