Geometrical Measurements of the TEC Elements

Transcription

1 A.Ostaptchouk, D.Pandoulas, S.Schael, R.Siedling I. Physikalisches Institut, RWTH-Aachen Goals internal survey external survey LINK calibration Means 3D CMM Cosmics Geodesy Procedure Conclusions Talk presented by A.O. for the TK TPO meeting on

2 - Goals - Goals of the geometrical measurements Internal survey: measurement of the TEC internal geometry External survey: measurement of positions of the TEC external fiducial marks w.r.t. the TEC internal coordinate frame LINK calibration: measurement of LINK element orientations

3 - Goals - Internal survey: measurement of TEC geometry for Quality Control (QC) of the TEC petals and discs Precise ( 50 µm) measurement of module rϕcoordinates in petal coordinate frame to provide a starting point for alignment with tracks Less precise ( 100 µm for rϕ-coordinates, 500 µm for z-coordinates) measurement of petals in the TEC coordinate system to provide the starting point for the TEC optical alignment system

4 - Goals - External survey: measurement of positions of the TEC external fiducial marks with 100 µm precision for fiducial mark rϕ-coordinates, and 200 µm precision for fiducial mark z-coordinates in the TEC coordinate system (for precise positioning of the TEC in the CMS coordinate frame) LINK calibration: measurement of LINK element orientations 20 µrad precision for tiltmeter ϕ-orientation w.r.t. gravity 100 µrad precision for periscope ϕ-and θ-orientations in the TEC coordinate system

5 -Means - Means of the geometrical measurements 3D Coordinate Measuring Machine (CMM) Cosmic Rays Geodesy

6 Geometrical Measurements - Clean Room - Parameters of Aachen clean room Class Temperature control: ± 1 oc Humidity control: ± 10% CMS Tracker Review September 2001

7 Geometrical Measurements - 3D CMM - 3D Coordinate Measuring Machine Type Wenzel RS-1618 Dynamic range mm3 Precision 20 + (L/50 mm) µm 70 µm Sensitive elements mechanical feeler or video camera

8 Geometrical Measurements - Cosmics Stand - Cosmics test-stand Triggered area mm2 Trigger granularity (10 X-counters) (10 Y-counters) µ-energy threshold 200 MeV (16cm steel)

9 -Geodesy - CERN survey group (Ch. Lasseur) provides different geodesic measurements, e.g. photogrammetry: Dynamic range several meters Resolution µm

10 - Internal Survey - Instruments: Survey of support structures Measurement of module positions 3D CMM Cosmics Targets for support structure measurements: Petals Discs TECs module inserts, petal mounts petal inserts, reference spheres reference spheres of the TEC discs Objectives of cosmics measurements: Module positions System test Optical alignment verification of the CMM survey one tower (1/16 TEC) read-out calibration: zero for installation

11 - Survey of Petals - Petal mounts Module inserts Procedure of petal survey: Petal position vertical Petal coordinate frame defined by 3 petal mounts Module insert positions in the petal coordinate frame

12 - Survey of Discs - Reference spheres Petal inserts Procedure of disc survey: Disc position Number of runs vertical or horisontal two overlapping runs Disc coordinate frame defined by 3 reference spheres Petal insert positions in the disc coordinate frame

13 - Survey of TECs - Reference spheres Procedure of TEC survey: TEC position Number of runs vertical or horisontal two or three overlapping runs TEC coordinate frame defined by reference disc (e.g. #5) Disc positions in the TEC coordinate frame

14 - Cosmics Stand - To fulfill the goals of measurements with cosmic rays measurement of the Si-odule positions system test of the TEC calibration of the optical alignment the minimal subsystem which has to be fully operational on the cosmic stand is one tower One tower (1/16 TEC) characteristics: Number of petals 9 Number of modules ~ 300 Number of FEDs 5-6 Cosmics rate ~.5 Hz

15 - External Survey - Goal of the external survey: precise measurement of the TEC external fiducials in the TEC coordinate system for precise positioning of the TEC in the CMS coordinate frame Instruments: 3D CMM photogrammetry Procedure has to be elaborated in a contact with the CMS survey group (Ch. Lasseur): Number of external fiducials Placement of the fiducials Measurement program

16 - LINK Calibration - LINK System tiltmeters periscopes LINK elements to calibrate: periscopes: 100 µrad precision for ϕ-and θ- orientations in the TEC coordinate system tiltmeters: 20 µrad precision for ϕ-orientation w.r.t. gravity

17 - Periscope Calibration - Periscope calibration: measurement of the sensor positions w.r.t. back-disc coordinate system using CMM or photogrammetry measurement of the laser spot positions in senor coordinate system

18 - Tiltmeter Calibration - Tiltmeter calibration: measurement of the back-disc reference incerts w.r.t. gravity using CMM or geodesy registration of the tiltmeters readings

19 - Conclusions - Geometrical measurements of the TECs provide necessary quality control of the TEC parts give a good starting point for both optical and track alignment make possible precise positioning of the TECs in the CMS coordinate frame allow calibration of LINK system elements The measurement tools are 3D Coordinate Measuring Machine Cosmic rays stand Photogrammetry The measurement procedures have to be developed and tested in contact with the CMS survey group