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					      Commissioning of the ALICE
              Detector




H.Taureg, LHCC Comp.Rev.4   Commissioning   1
March 2004
                    Commissioning Steps
1       Tests at construction site
      –      Agreed test procedure
      –      Before system comes to CERN
      –      Not treated here
2       Tests at CERN at the surface
      –      Check before moving to UX25
3       Tests in final location in UX25
      A      Individual sub-systems
      B      Several systems together
      C      The whole detector

H.Taureg, LHCC Comp.Rev.4     Commissioning   2
March 2004
                    Commissioning Steps
• Soft boundary towards installation
      – Close collaboration with installation team
• Services are considered as part of the
  sub-detector
• Trigger, DAQ, HLT, ECS, DCS
• Commissioning of magnets will be
  completed by the end of 2004

H.Taureg, LHCC Comp.Rev.4   Commissioning            3
March 2004
                    Step 2 Commissioning
• Examples of tests at the surface
      – Space frame
            • Load test
            • TPC, TRD, TOF installation
            • ITS installation
      – TOF
      – TPC



H.Taureg, LHCC Comp.Rev.4     Commissioning   4
March 2004
                    Step 2,
                    Space Frame in SXL2




H.Taureg, LHCC Comp.Rev.4   Commissioning   5
March 2004
                    Step2, Space Frame
• Load Test
      – Check space frame dimensions under load
      – Insert water filled tanks representing TRD and
        TOF super-modules
      – Tanks have equivalent weight and “cog” in the
        same position as real super-modules




H.Taureg, LHCC Comp.Rev.4   Commissioning            6
March 2004
                    Space frame, load test




H.Taureg, LHCC Comp.Rev.4   Commissioning    7
March 2004
                    Space Frame: TRD, TOF
• TRD and TOF installation
      – Install rails for TRD and TOF
      – Insert shell of super-modules
      – Check installation procedure and tools
      – Check clearances




H.Taureg, LHCC Comp.Rev.4   Commissioning        8
March 2004
                     Space Frame: TRD, TOF




H.Taureg, LHCC Comp.Rev.4   Commissioning    9
March 2004
                    Space Frame: TPC
• Insert TPC into space frame
• Exercise TPC displacement




H.Taureg, LHCC Comp.Rev.4   Commissioning   10
March 2004
                    Space frame, TPC




H.Taureg, LHCC Comp.Rev.4   Commissioning   11
March 2004
                    Space Frame: ITS
• Exercise ITS installation
      – TPC
      – Front Absorber
      – Model of ITS
      – Model of the beam pipe
      – Installation tooling for all components



H.Taureg, LHCC Comp.Rev.4   Commissioning         12
March 2004
                       Space Frame: ITS




H.Taureg, LHCC Comp.Rev.4    Commissioning   13
March 2004
                    Step 2 Commissioning
• Commissioning of sub-systems
      – On the surface
      – Alone and together with others
      – With DCS and DAQ
      – Detector and electronics
      – With all services
      – Sub-systems outlined their plans and needs
      – Discussed in the TB

H.Taureg, LHCC Comp.Rev.4   Commissioning            14
March 2004
                    Step 2: TOF
Surface tests at CERN
Modules
• Each TOF module tested individually at CERN with cosmics and pulser (about 5
   weeks per group of 4 modules piled up inside a cosmic test facility)
• required 100 m2 + gas system + moderate temperature control + clean room
   (mostly already available in Build 167).

SuperModules
• TOF SuperModule assembled at CERN , including readout crate
• Each SuperModule tested for basic functionality prior to installation:
      –   Gas and water tightness
      –   HV test in air : look for possible short circuits
      –   LV connections – power distribution
      –   Pulse signal injected into MRPCs to check noise and TOF crate readout
•   Estimate of space/time required at CERN :
      –   100 m2 for assembly + 300 m2 for storage during phase III (if needed)
      –   60 days/SuperModule assembly + tests




H.Taureg, LHCC Comp.Rev.4                  Commissioning                          15
March 2004
                      Step 2: TOF

 TOF cosmic test stand
                                           Cosmic particle



                                            TOF modules
Trigger detectors



                                               Muon filter




 • The mechanical frame is already built

 • Trigger counters are under construction



  H.Taureg, LHCC Comp.Rev.4                 Commissioning    16
  March 2004
                    Step 2: TPC
• At SXL2, commissioning during pre-installation:
      – Nov 04 to Apr 05
            • ROC mechanical installation:
            • leak tests, survey
      – May-Aug 05: FEE installation. Full DCS/DAQ for each ROC
      – Required (for 2 ROC being tested at the same time:
            • Running DAQ, 2 optical links
            • Standalone DCS
            • Final Ne/CO2 gas system
              temporary lines to SXL2
• SXL2 pre-commissioning Sep05-Feb06
      – Tests with 2 sectors, laser and cosmic triggers (ACORDE)
      – Requirements as above, plus
            • Cosmics trigger, movable to serve different sectors


H.Taureg, LHCC Comp.Rev.4               Commissioning               17
March 2004
                    Step 2: TPC




H.Taureg, LHCC Comp.Rev.4   Commissioning   18
March 2004
                    Step 3 Commissioning
• In UX25
• Interleaved with installation work
• Installation has priority during the “day” till
  Installation Phase 4 (Nov. 2006)
• Get sub-systems working individually asap
  after installation
• Use ACORDE for cosmic trigger

H.Taureg, LHCC Comp.Rev.4   Commissioning       19
March 2004
                    Step 3: HMPID
• 2-3 weeks with the cradle on rails outside L3:
      –   February 2006
      –   Ancillary systems commissioning
      –   DCS commissioning
      –   Noise level measurement (pedestal map)
• Cradle moved in the final position:
      – March 2006
      – Optical survey of external alignment marks
      – Local deformation measurement → realignment of
        header tubes

H.Taureg, LHCC Comp.Rev.4    Commissioning               20
March 2004
                    Step 3: HMPID




H.Taureg, LHCC Comp.Rev.4   Commissioning   21
March 2004
                    Signal “cable” lengths

• Detectors participating in L0 generation
      – Equal length of traces, cables or fibers to
        “processing stage” by construction
        Detector        cables         cable timing
            T0                    24/2           ≤ 1 ns
            V0                    72/2           ≤ 1 ns
            PHOS            17920/40/5           ≤ 1 ns
            μ-arm            20992/16            ≤ 1 ns
      – Time critical connection to CTP (t ≤ 800 ns)
            • Only one cable per sub-detector
H.Taureg, LHCC Comp.Rev.4        Commissioning            22
March 2004
                         PHOS cables
                                                      Fixed delay to CTP ( +/- 6 ns ?)


                                                               Input @ 20 MHz          Out to CTP at fixed time relative
                                                                                       to BCO : 600 ns
       BCO                  400 ns   to Processing Unit                                                           CTP
                                                                               FPGA
               t=0                                                                                     800 ns

               Shower   APD Shaper A.Sum      Altro ADC Mux                                     NRZ ( L0 )   to
                                                5.5*Sampling        2 ( 3 ) -deep summing                    Central Trig. Pr.
                                                                     pipeline                                ~ 40 m = (200 ns)
                                                clock =
                                                               50
                        ~ 75 ns                 275 ns                       200 ns

                                                                     4*4 region summing                peaking time lookup
                                        5.5*50 ns sampling

     1/2 LHC
     20 MHz



                                                                    “Current”L0 Process
                                           40 MHz Mux                            175 ns                Time critical
                                                                                                       connection
                                  FEE      TRU
  Arrival times equalized
H.Taureg, LHCC Comp.Rev.4                                    Commissioning                                                       23
March 2004
                     PHOS cables
crystal
                                              Cables of
                                              equal length
                                              (~10 cm) to
                                              better than 1 cm


 FEE card
                                             Cables of equal
                                             length (~50 cm) to
                                             better than 1 cm
Trigger card




 H.Taureg, LHCC Comp.Rev.4   Commissioning               24
 March 2004
                    Signal “cable” lengths

• Detectors not participating in L0
      – No effort to equalize arrival times in hardware
        at the 1 ns level
      – Equalization by calibration




H.Taureg, LHCC Comp.Rev.4    Commissioning            25
March 2004
                                     TPC cables
                                                       Different trace lengths from pad to Kapton cable,
                                                       few nsec difference

                 DETECTOR                               Front End Card (128 CHANNELS)
drift region                                                                                                  Custom
    88ms                         Capton
                                  cable    8 CHIPS (16 CH / CHIP)             8 CHIPS (16 CH / CHIP)         Backplane

                                                                                                   ALTRO
 gating grid




                                                PASA                ADC             Digital            RAM
                         anode
                          wire                                                      Circuit                        RCU

                                              CUSTOM IC
     570132 PADS                  pad
                                            (CMOS 0.35mm)                  CUSTOM IC (CMOS 0.25mm )           (3200 Ch / RCU)
                                  plane




                                           No equalization of arrival time at this point,
                                           Up to 35 cm difference in path lengths
               H.Taureg, LHCC Comp.Rev.4                            Commissioning                                        26
               March 2004
                    Trigger commissioning
• Timing scheme developed
      – Extensive discussions between trigger and
        sub-detectors and in the TB
      – Internal note documents scheme
      – Final timing in two steps (for L0 trigger
        detectors)
            • Needs some beam
            • Phase alignment of sub-detectors
            • Alignment with identical bunch crossing
H.Taureg, LHCC Comp.Rev.4      Commissioning            27
March 2004
                    Timing
• Phase alignment
      – Align L0 trigger from all trigger detectors to
        same clock phase using interactions
• Alignment to same bunch crossing
      – Use gap in bunch train to align on same
        bunch crossing
      – shift L0 signals in steps of 25 ns at CTP input


H.Taureg, LHCC Comp.Rev.4    Commissioning                28
March 2004
                    DAQ commissioning
• Have detailed list of requirements for
  capacity and schedule
      – Standalone tests in construction sites, test
        beams, commissioning sites
      – Tests with several sub-systems together, e.g.
        test beam of all 3 ITS systems this year
      – Commissioning schedule in UX25



H.Taureg, LHCC Comp.Rev.4   Commissioning               29
March 2004
                    Conclusions
• Commissioning work has been defined
• Requirements are known
• Influence of cable length has been taken
  into account
• Timing procedure has been elaborated
• DAQ needs will be met at all stages


H.Taureg, LHCC Comp.Rev.4   Commissioning    30
March 2004

				
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posted:2/15/2013
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