IEEE NSS Hohlmann alignment Hawaii Oct 07 final 000 by 9kk4nW9

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									                                                      Aligning the CMS Muon Endcap Detector                                                                                                                                                                                                                                                                                                                                                                                                                                                        Nucl. Sci. Symposium
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   Oct 27 – Nov 3, 2007
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     Honolulu, Hawaii
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          N15-257




                                                          with a System of Optical Sensors
                                                                                                           M. Hohlmann1, G. Baksay1, S. Guragain1, J. Bellinger2, D. Carlsmith2, F. Feyzi2, R. J. Loveless2,
                                                                                                                   D. Northacker2, V. Andreev3, X. Yang3, D. P. Eartly4, O. Prokofiev4, V. Sknar5
                                                                                                                               1Florida Inst. of Technology, Melbourne, FL, 2U. of Wisconsin, Madison, WI, 3U. of California, Los Angeles, CA,
                                                                                                                                   4Fermi National Accelerator Lab, Batavia, IL, 5Petersburg Nuclear Physics Institute, St. Petersburg, Russia
                          Compact Muon Solenoid




          Reconstruction of Muon Chamber zCMS - Positions
                                                                   First CCD pixels
                                                                                                                                                                                                                                                                                                                                  Reconstructed positions of outer CSC PCB skins


                                                                                                                                                                                                                                                                                                                                                                                                                                                                         (no PG avail.)
                                                                      Laser hits                                                                                                                                                                                                                                           PG measurements of coded
                                   bad hits                      (shifted to the sides                                                                                                                                                                                                                                     targets on outer CSC PCB skins
                                   not used                       of CCDs for display)
                                   in fit
                                                                              CCD2       CCD4                                                                                                                                                                                                                                                                                                                                                                                                                        PG of TPs
                                                                  CCD4
                                                          CCD2                                                                                                                                                                                                                                                                                                                                                                                                                                                       determines
                                                                                                                                                                                                                                                                                                                                      Solid triangles:                                                                                                           Open triangles:                                     global zCMS
                                                                                                                                                                                                                                                                                                                                   Reconstructed tops                                                                                                              PG meas. of                                       position of
                                                                                                                                                                                                                                                                                                                                  of CSC Alignment pins                                                                                                         CSC Alignment pins
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     entire system
                                                                                                                                                                                                                                                                                                                                                                                               First CCD pixels
                                                                   fitted position

                                                                                                                              B=0T
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     B=0T
                                                             Note: The lasers were tilted                                                                                                                                                                                                                                                                           CCDs
                                        DCOPS                 towards the chambers on
                                                                                                                                                                                                                                                                                                                    Solid triangles: Reconstructed tops of DCOPS boxes                                         Recon. & PG match well !
                                                             purpose to compensate for
                        Ref. CCD
                                         CCDs                   disk bending at B=4T !
                                                                                                                   Ref. CCD
                                                                                                                                                                                                                                                                                                                                         Open triangles: PG measurement of tops of DCOPS boxes



                                                                                                                                                                                Resolution
                                                                                                                                                          All tolerances and           Input Tolerance                 Uncertainties returned by fit
Laser 2                                                                                                                                                   uncertainties in μm        specified in COCOA
                                                                                                                                                                                    Reconstruction model                   Ideal Case     B=0T   B=4T

                                                                                                                                                  Transfer plate                                300                             0         290    290                                                                                                                                      B=0T fit positions
                                                    CCDs 2 in 10 DCOPS                                                                                                                                                     (kept fixed)                                                                                                                                  ~ 13mm
                                                                                                                                                                                                                                                                                                                                                                                            B=4T fitted
                                                                                                                                                                                                                                                                                                                                                                                           CSC positions
                                                                                                                                     Laser 5      Laser                                         200                            48          50     50
                                                                                                                                                                                                                                                                                                                                                                     Disk bending is reconstructed !
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  This assumes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  that the TP’s do
                                                                                                                                                  Reference DCOPS                               20                             20          20     20                                                                                                                                                                                                                                                              not shift in z &
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  do not rotate!
                                                                                                                     Good hits !
                                                                                                                                                  Chamber DCOPS                                 100                            95          95     95
Laser 2

                                                                                                                                                  Total tolerance by simply                     388                           108         310    310                                                                                                                                                                                                                                                                 B=4T
                                                                                                                                                  adding all in quadrature
                                                                  CCDs 4
                                                                                                                                                  Tolerance by adding in quad.                  371                            95         306    306
                                                                                                                                     Laser 5      & using 1/sqrt(2) for 2 DCOPS

                                                                                                                                                  CSC uncertainties                                                            90         272    272
                                                                                                                                                  actually returned by fit



                        Raw data: Laser profiles                                                                                                                                  Precision                                                                                            CSC & DCOPS Reconstruction

 Reconstruction vs. Photogrammetry Measurements
                                                                                                                                                                                                                                                                          PG: Displacements from nominal positions
                                                                                                                                Current Reconstruction Performance                                                                                                            Photogrammetry (PG) measurement uncertainties are xPG = yPG = zPG = ± 0.3 mm

                                                                                                                                     for axial zCMS - coordinate:                                                                                                                 Chamber Alignment Pins
                                                                                                                                                                                                                                                                              Δy = yPG – ynom. vs. Δx = xPG – xnom.
                                                                                                                                                                                                                                                                                                                    Chamber Coded Targets
                                                                                                                                                                                                                                                                                                                       Δz = zPG - znominal

                                                                                                                                       Resolution & Sensitivity to relative motion:
                                                                                                                                                                                                                                                                                                                                                                                                                                              Mean       0.01
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 Note: A systematic shift was
                                                                                                                                                                                                                                                                                                                                                                                                                                              RMS        0.94                    subtracted for each chamber
                                                                                                                                                                                                                                                                                                                                                                                                                                  30
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 type: Z = Z PG – Z Mean



                                                                                                                                                       ~ 60 μm
                                                                                                                                                                                                                                                                                                                                                                                                                                  25




                                          683 μm
                                                                                                                                                                                                                                                                                                                                                                                                                                  20




                                                                                                                                                                                                                                                                                                                                                                                                                      Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                  15


                                                                                                                                                                                                                                                                                                                                                                                                                                  10

                                                                                                                                     Precision of chamber position reconstruction:                                                                                                                                                                                                                                                5



                                                                                                                                                      ~ 270 μm                                                                                                                                                                                                                                                                    0
                                                                                                                                                                                                                                                                                                                                                                                                                                               -2        -1                 0             1         2            3
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Z, mm




                                                                                                                                                                                                                                                                      Conclusion: Accuracy of chamber installation on the disks in X,Y,Z is ~ 1 mm (rms)
                                                                                                                                     Accuracy from check against Photogrammetry:                                                                                      8000
                                                                                                                                                                                                                                                                                             ME +1 Station
                                                                                                                                                                                                                                                                                                                                                                 8000
                                                                                                                                                                                                                                                                                                                                                                                       ME +2 Station
                                                                                                                                                                                                                                                                                                                                                                                                                                                                          8000
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               ME +3 Station


                                                                                                                                                      ~ 680 μm                                                                                                        6000

                                                                                                                                                                                                                                                                      4000
                                                                                                                                                                                                                                                                              ME+1 Station                                                    Z, mm


                                                                                                                                                                                                                                                                                                                                                 4.0
                                                                                                                                                                                                                                                                                                                                                                 6000

                                                                                                                                                                                                                                                                                                                                                                 4000
                                                                                                                                                                                                                                                                                                                                                                         ME+2 Station                                                                Z, mm               6000

                                                                                                                                                                                                                                                                                                                                                                                                                                                                          4000
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  ME+3 Station                                          Z, mm



                                                                                                                                                                                                                                                                                                                                                                                                                                                        4.0                                                                                 4.0
                                                                                                                                                                                                                                                                      2000                                                                                       2000                                                                                   3.0               2000                                                              3.0
                                                                                                                                                                                                                                                                                                                                                 2.0
                                                                                                                                                                                                                                                                                                                                                                                                                                                        2.0                                                                                 2.0
                                                                                                                                                                                                                                                                                                                                                        Y , mm




                                                                                                                                                                                                                                                                                                                                                                                                                                                                 Y, mm
                                                                                                                                                                                                                                                              Y ,mm




                                                                                                                                                                                                                                                                         0                                                                                          0                                                                                   1.0                  0                                                              1.0


                                                                                                                                               (Accuracy required by design: 1 mm)
                                                                                                                                                                                                                                                                                                                                                 0                                                                                                                                                                                          0
                                                                                                                                                                                                                                                                                                                                                                                                                                                        0
                                                                                                                                                                                                                                                                      -2000                                                                                      -2000                                                                                                   -2000                                                              -1.0
                                                                                                                                                                                                                                                                                                                                                                                                                                                        -1.0
                                                                                                                                                                                                                                                                                                                                                 -2.0                                                                                                                                                                                       -2.0
                                                                                                                                                                                                                                                                                                                                                                                                                                                        -2.0                                                                                -3.0
                                                                                                                                                                                                                                                                      -4000                                                                                      -4000                                                                                                   -4000
                                                                                                                                                                                                                                                                                                                                                                                                                                                        -3.0                                                                                -4.0

                                                         Discrepancy zPG – zreco (mm)
                                                                                                                                                                                                                                                                                                                                                 -4.0
                                                                                                                                                                                                                                                                                                                                                                                                                                                        -4.0
                                                                                                                                                                                                                                                                      -6000                                                                                      -6000                                                                                                   -6000

                                                                                                                                                                                                                                                                                        Coded Targets                                                                              Coded Targets                                                                                              Coded Targets
                                                                                                                                                                                                                                                                      -8000                                                                                      -8000                                                                                                   -8000
                                                                                                                                                                                                                                                                          -8000 -6000 -4000 -2000     0      2000   4000   6000   8000                               -8000 -6000 -4000 -2000     0      2000   4000    6000            8000                                  -8000 -6000 -4000 -2000     0     2000 4000 6000 8000
                                                                                                                                                                                                                                                                                                    X , mm                                                                                     X , mm                                                                                                  X, mm




              Hardware Alignment System for Muon Endcaps
                                                  Ref.
                                                                                                                                                                                         Laser 2
                                                                                                                                                                                                      Note: only a small
                                                                                                                                                                                                      sample of analog
                                                                                                                                                                                                                               Muon Endcap instrumented                                                   Muon Endcap stations:                                                                                                                                                                                                  ME-
                                                 DCOPS

    2 Crosshair
                                                                                          ME+2 Straight Line Monitor                                                                                  sensors is shown
                                                                                                                                                                                                                               w/ Cathode Strip Chambers                                                                                  ME+2
    Lasers (adjustable)
                                                                                                                                                                                                                                                                                                                      ME+3                                         ME+1
                                                                                                                                                            R-sensors


                                                   Z-sensors
                                                                                                                                                                                                                                                                                                          ME+4
                                                                                                                                                                                  ME+2 SLM2-5

               Z-tube




                     Clinometer
                                      Transfer                                                             Chamber DCOPS’s                                           Laser 5            Crosshair laser lines:                                                                                      +z
                                        Plate                                                                                                                                           • Transfer lines
                                                                                                                                                                                        • Straight Line Monitors (SLMs)

                                                           Transfer                                    Mounting
                                                             Line                                       Tower
                                                            DCOPS

                                                                                                R-sensor
                                                                                                                                                            Laser Line System:
                                                                                                                                                            • 3 Optical Straight Line                                                                                                                                                                                                                                                                 Muon Endcaps
                                                                                                                                                              Monitors (SLMs) across                                                                      ME+2                                                                                                           Yokes
                                                                                                                                                              each disk
                                                                                                                                                            • 2 Lasers & 10 CCD DCOPS’s
                                                                                                                                                                                                                                                 CCD3
                                                                                             Front
                                                                                            Chamber
                                                                                                                                                              in each SLM
                                                                                                                                                            • 6 DCOPS Transfer Lines
                                                                                                                                                              connecting all ME disks                                           CCD2

                                                                                                                               Analog Sensors:                                  DCOPS:                                                                                                                                                                                                                  •      468 CSCs of 7 different types & sizes
                                                                                                                                                                                                                                                                      CCD4                                                                                                                              •      > 2,000,000 wires (50 µm Ø )
                                                                                                                               • 84 Radial Chamber Position Monitors            • 4 × 1-d CCDs                                                                                                                                                                                                          •      6,000 m2 sensitive area
                                                                                                                               • 84 Axial Disk Position Monitors                • 2048 CCD pixels                                                                                                                                                                                                       •      1 kHz/cm2 rates
                                                                                                                               • 60 Clinometers for Transfer Plates             • 14 μm pixel pitch                                                    CCD1                                                                                                                                             •      2 mm and 4 ns resolution (L1 trigger)
     Chamber Alignment Pins                   Chamber Coded Targets                             DCOPS Target                                                                                                                                                                                                                                                                                            •      ~ 100 m resolution (offline)

                        Photogrammetry Targets                                                                                                        Digital CCD-based Optical Position Sensor                                                                                                                                              Cathode Strip Chambers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     M .H . fecit - Oct 2007

								
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