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Status of the Silicon Strip Detector at CMS

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Status of the Silicon Strip Detector at CMS Powered By Docstoc
					Status of the Silicon Strip
    Detector at CMS
             INSTR08
         Novosibirsk, Feb08

            Hans Jürgen Simonis
            Universität Karlsruhe
 On behalf of the CMS-Tracker Collaboration



          H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
CMS -- Compact Muon Solenoid




       H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                        The CMS Si-Strip Tracker


                                                                                 What is in this box?


                                                                                      Size:
                                                                                      6m x 2.5m



                                                                                   200 m2 of active Silicon
                                                                                   15.100 Si Modules
                                                                                   75.000 APV FE chips
                                                                                   9.6 M readout channels
                                                                                   26 M wirebonds
                                                                                   37.000 Optical links

(status september 07)
                                  required temperature: –10 °C on the Silicon surface
                            H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                     The Tracker Constituents
                                        how is it organized?

                                                           hermetically closed system
           TOB (Tracker Outer Barrel)                      tracking combines to outer Muon system
                                                           resolution of pt ~1.5% at 100GeV
           6 layers
           5200 modules


                r (mm)

SS Modules red
DS Modules blue
(100 mrad stereo angle)
                                                                                                   h
                                                                                                       Beam
                          IP                                                               z (mm)

     TIB (Tracker Inner Barrel)        TID (Tracker Inner Disks)                    TEC (Tracker EndCap)
     4 layers                          2x3 disks                                    2x9 disks
     2700 modules                      800 modules                                  6400 modules

                               H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
             Tracker Production: Modules

                                                                                        TOB             TEC

                                                                                     TIB TID




                                                                                   6400 TEC Modules
                                                                                    800 TID Modules
                                                                                   10 different geometries

5200 TOB Modules                                                                              R2          R3
                                                                              R1
example: „stereo“-type          2700 TIB Modules                                                               R4
512 strips/sensor               768 strips/sensor




                                                                                        R6         R5
                         H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08        R7
           Tracker Production: TID
                                                                                                 TID
             we have 2 TIDs (z+ / z-) with 3 disks each
             each disk consists of 3 rings of modules
             each ring is mounted on a carbon fiber annulus




The free space between modules is covered with
overlapping modules on the backside.
Modules are directly mounted on the cooling pipes.                        one TID ready for mounting to TIB

                             H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                Tracker Production: TIB
                                                                                                    TIB
The Inner Barrel consists of 4 layers of modules (“shells”)
at radii: (20 cm < r < 55 cm)
The 2 inner shells are equipped with double modules (stereo)
Each shell is produced in 4 large pieces: “half-shells” (2 for z+ and 2 for z-)
Modules are mounted with overlap in . (surface tilted wrt tangent)
Modules on inner and outer surface overlap in z.
Starting from shell-4, shells 3 - 2 - 1 are sequentially slid into the volume.

                                                                  shell: 4               3      2




handling of components „on-shell“ is a delicate procedure           Half of the TIB seen as a Matrjoschka (матрёшка)

                                    H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
               Tracker Production: TOB                                                                TOB



The Outer Barrel spans the region (55 cm < r < 116 cm) with 6 layers
Again, the 2 inner layers consist of double modules (stereo)
A large CF support structure is loaded with 688 “rods” as sophisticated substructures
The concept of rods (8 different types) allowed a distributed production scheme




Rod-genesis: frame                                    The 2 outer layers were the first to be equipped with rods
+ interconnectboard + 6(12) modules
                                      H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
              Tracker Production: TEC                                                           TEC


The 2 Endcaps consist of 9 Disks each
Wedge-shaped modules form 7 concentric rings with all strips pointing to the beam axis
Rings 1,2 and 5 have double modules („stereo“-rings)
„Petals“ represent the substructures which allow for distributed production




  we have 288 Petals of 8 different                A fully equipped Endcap
  types, equipped with 19-27                       The 16 Petals of Disk-1 can nicely be seen
  modules
                               H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                       Tracker Production:
                          Just plug everything together
                                                       The support tube carries all the tracker
                                                       elements and serves as thermal shield
                                                       (with active cooling) towards the ECAL:
                                                        -15º inside; +18º outside




The assembly took place in a large
clean room (TIF) where all aspects of
system tests could be performed




                                                     Tracker ready for transportation to CMS site, 20 km from CERN

                             H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
CF plates:                            Kapton:                              FE-APV:                    Control ASICS:
FactoryBrussels                      FactoryAachen, Bari                 Factory  IC,RAL           Factory  Company (QA)
                               CF cutting
              CF cutting       Factory
                                                        Sensors:           Hybrids:                       Pitch adapter:
              Factory             Frames:               Factories          Factory-Strasbourg             Factories Brussels
                                  Brussels,Pisa,
                                  Pakistan
                                                                          CERN
                                                                                                                            Louvain
Sensor QAC                 Pisa                    Perugia                       Vienna                      Karlsruhe      Strasbourg
                                                                                                                            Firenze

Module
              FNAL      UCSB                 Perugia        Bari                    Vienna         Lyon              Brussels
assembly


Bonding
              FNAL   UCSB       Padova Pisa Torino Bari              Firenze Vienna Zurich Strasbourg Karlsruhe Aachen HH
& testing


Integration    ROD INTEGRATION                   TIB-TID INTEGRATION                  Louvain     PETALS INTEGRATION         Aachen
into
mechanics        FNAL          UCSB              Florence     Pisa   Torino
                                                                                       Brussels    Hamburg    Strasbourg   Karlsruhe




Sub-assemblies       TOB assembly              TIB/TID assembly                   TEC assembly                  TEC assembly
                               CERN                          Pisa                         Aachen                  Lyon@CERN


                                                            TK ASSEMBLY
                                                                   CERN TIF
                                                                                                   Move to Pit and Insert
                                            H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
        Cosmics in the TIF – (Tracker slice test)
       (summer 2007, on surface, without magnetic field)
            already large (~15%) Tracker System




•   only Silicon Strip Tracker involved
•   2161 modules – 24,75 m² active area
•   measurements at different temperatures down to -15°C
•   trigger rate 6.5 Hz ; 4.5 M events

                     H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                      Signal to Noise

       TOB                          TIB




                                                                    1000 1200
                                                                      noise [e-]
                                                                          800
                                                                                   10   14          18
        TEC                             TID                                                  Strip length [cm]



                                                                        noise charge versus strip length;
                                                                        all TOB and TEC geometries



Average value: S/N~30 for all subsystems




                     H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                    Tracking in TIF
           cosmics are rather different than pp-collisions
            special tracking algorithm has been developed
            module orientation not ideal (especially TEC and TID)


                                                                          preliminary
                                                  1.04

                                                  1.00

                                                  0.96
                                                                                               ▼Data
                                                          TOB efficiency given a TIB track     ▲Simulation
                                     Efficiency
                                                  0.92

                                                           1.2           1.3            1.4      1.5         


                                                  1.04

                                                  1.00

     comparison of measured                       0.96
conditional track reconstruction                         TIB efficiency given a TOB track
                                                  0.92
         efficiencies (TIB/TOB)
                                                           1.2           1.3            1.4      1.5         
                with simulations
                                                                                 polar angle

                   H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
Status: Tracker insertion 16.12.2007




         H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
            Installation Status Z- ; 25 Feb.2008
              -4                      -6                     -7                        Lots of
                                                                                       Connections:
                                                                         -8
                                                                         Z-            • 980 pipes
      -3
                                                                                       • 3347 fibers
                                                                                       • 2330 cables

 -2                                                                           -9




                                                                                  Sequence:
                                                                                  → Barrel fibres
                                                                                  → Pipe connection
-18
                                                                              -11 → Pipe insulation
                                                                                  → Barrel cables
                                                                                  → TEC fibres
                                                                                  → TEC cables
      -17
                                                                        -12

             -16                                      -13
                                                                                   p    = partially done
                     -15               -14                                         w    = in work
                   H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
               Status Feb.25

• Tracker is in final position inside CMS with an
  accuracy of 1mm
• Fibers for Barrel, and almost all cooling pipes
  are connected
• Services for Endcap are the last to be finished
• Beampipe installation foreseen mid-April
• BUT! CMS-closure test interferes with Tracker
  progress (in May)
• Cosmic Runs (CRAFT) are foreseen until first
  beam (June/July 2008)

               H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
          About Detector upgrade (SLHC)
          (our silicon tracker will be dead after 10 years of LHC operation)

The upgrade of the LHC machine cannot be in energy, but in luminosity:
                           1034  1035 [p / s • cm2]
The way how to reach that is not yet clear (12.5ns, 25ns, 50ns bunches, …)

Higher occupancy ~10000 tracks per bunch crossing!
 we need shorter strips  more electronic channels  more power required
but: tracker material budget is already at its limits
studies on new supply schemes have started (cooling; DC-DC-converters etc)

                                             1034                                            1035




 LHC: ~20 soft interactions superimposed                   SLHC: ~90 soft interactions superimposed
 on interesting event ( --> 1000 tracks/bc)                on interesting event (could be ~200 or
                                                           even 400; depending on bunchstructure)

                           H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                  About Detector upgrade (II)
   Higher irradiation Dose  In inner region (r <~ 40 cm) we need new rad-hard
   sensor-material  see RD50 activities (->Talk from G. Casse after lunch)

   In the outer region existing material (p-in-n float zone) can possibly be used.
   n-in-p and / or Magnetic Czochralski are in discussion

   But most challenging is the requirement that the SCMS-tracker has to
   contribute to the L1-trigger (detect high pt-tracks)
    we need a new Tracker design

   several layouts are discussed:


                           TOB
 Extra pixel layer,         TOB
bigger pixels, long         TIB
pixels/short strips,        TIB                                                  3 Super-layers of stacked
 & 1-2 triggering            PD                                                    doublets - M. Mannelli
 layers - J. Nash



                            H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                                                16. December 2007: Tracker in CMS




H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
Backup Material




 H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                   Silicon Sensors
p-in-n type silicon
<100> – orientation
1.5 – 3.2 kΩcm resistivity; 320 µm thickness
4.0 – 8.0 kΩcm resistivity; 500 µm thickness




                                                     Bias Voltage



                      H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                   The Readout scheme
                                                             amplify, shape and store




                                                                                  Data branch
A Readout-hybrid with 4 APV chips                  Control branch
                                                   (clock, trigger, …)



                             H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
                     The Material budget

the contribution of different constituents is color-coded:




                                                                     support

                                                                     cooling

                                                                     cables




                H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
Signal / Noise for the different Tracker elements at various temperatures
corrected for incident angle



   Scint. Conf. B, Room   Scints Conf.
   Temp                   C,
                                                 10°              0°       -10°   -15°
                          Room Temp




TIB → StoN ~ 27; TOB → StoN ~ 31; TEC → StoN ~ 31

                          H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
   MTCC – MagnetTest and Cosmic Challenge
             (summer 2006, still in surface hall)
          small Tracker system within CMS-Magnet



              4 TOB rods



            2 TIB segments
                                       2 TEC petals


• all CMS-subsystems involved (incl. ECAL, HCAL, Myon-System)
for Tracker:
• 1% of electronic channels (~105) connected
• 133 modules in total ( 0.75 m2 Si area)
• 25 M events at different magnetic field values up to 3.8T
• check of noise behavior
• check software (readout, data handling, tracking algorithms)

                     H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08
Petal assembly




H.J.Simonis, CMS Collaboration, Novosibirsk Feb.08

				
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