Geometrical Measurements of the TEC Elements Goals internal survey external survey LINK calibration Means 3D CMM Cosmics Geodesy Procedure Conclusions.

Geometrical Measurementsof the TEC Elements

Goals internal survey external survey LINK calibration

Means

3D CMM Cosmics Geodesy

Procedure

Conclusions

A.Ostaptchouk, D.Pandoulas, S.Schael, R.Siedling

I. Physikalisches Institut, RWTH-Aachen

Talk presented by A.O. for the TK TPO meeting on 01.11.01

Geometrical Measurements of the TEC Elements

- 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


- Goals -

Internal survey: measurement of TEC geometry for

Quality Control (QC) of the TEC petals and discs

Precise ( 50 m) measurement of module rcoordinates in petal coordinate frame to provide a starting point for alignment with tracks

Less precise ( 100 m for r-coordinates, 500 m for z-coordinates) measurement of petals in the TEC coordinate system to provide the starting point for the TEC optical alignment system


- Goals -

External survey: measurement of positions of the TEC external fiducial marks with

100 m precision for fiducial mark r-coordinates, and 200 m 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 rad precision for tiltmeter -orientation w.r.t. gravity 100 rad precision for periscope - and -orientations in the TEC coordinate system


- Means -

Means of the geometrical measurements

3D Coordinate Measuring Machine (CMM)

Cosmic Rays

Geodesy

CMS Tracker Review September 2001


- Clean Room -

Parameters of Aachen clean room

Class 100 000 Temperature control: 1 oC Humidity control: 10%


- 3D CMM -

3D Coordinate Measuring Machine Type Wenzel RS-1618 Dynamic range 2500 1600 1800 mm3

Precision 20 + (L/50 mm) m 70 m Sensitive elements mechanical feeler or video camera


- Cosmics Stand -

Cosmics test-stand

Triggered area 2200 2200 mm2

Trigger granularity (10 X-counters) (10 Y-counters) -energy threshold 200 MeV (16cm steel)


- Geodesy -

CERN survey group (Ch. Lasseur) provides different geodesic measurements, e.g. photogrammetry:

Dynamic range several meters

Resolution 50 - 100 m


- Internal Survey -

Instruments:

Survey of support structures 3D CMM

Measurement of module positions Cosmics

Targets for support structure measurements:

Petals module inserts, petal mounts

Discs petal inserts, reference spheres TECs reference spheres of the TEC discs

Objectives of cosmics measurements:

Module positions verification of the CMM survey

System test one tower (1/16 TEC) read-out Optical alignment calibration: zero for installation


- Survey of Petals -

Procedure of petal survey:

Petal position vertical

Petal coordinate frame defined by 3 petal mounts Module insert positions in the petal coordinate frame

Petal mounts

Module inserts


- Survey of Discs -

Procedure of disc survey:

Disc position vertical or horisontal

Number of runs two overlapping runs

Disc coordinate frame defined by 3 reference spheres Petal insert positions in the disc coordinate frame

Reference spheres

Petal inserts


- Survey of TECs -

Procedure of TEC survey:

TEC position vertical or horisontal

Number of runs two or three overlapping runs

TEC coordinate frame defined by reference disc (e.g. #5) Disc positions in the TEC coordinate frame

Reference spheres


- Cosmics Stand -

One tower (1/16 TEC) characteristics:

Number of petals 9

Number of modules ~ 300

Number of FEDs 5-6 Cosmics rate ~ .5 Hz

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


- External Survey -

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

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


- LINK Calibration -

LINK elements to calibrate:

periscopes: 100 rad precision for - and - orientations in the TEC coordinate system

tiltmeters: 20 rad precision for -orientation w.r.t. gravity

LINK System

tiltmeters

periscopes


- 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


- Tiltmeter Calibration -

Tiltmeter calibration:

measurement of the back-disc reference incerts w.r.t. gravity using CMM or geodesy

registration of the tiltmeters readings


- 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

Geometrical Measurements of the TEC Elements Goals internal survey external survey LINK calibration Means 3D CMM Cosmics Geodesy Procedure Conclusions.

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Geometrical Measurements of the TEC Elements Goals internal survey external survey LINK calibration Means 3D CMM Cosmics Geodesy Procedure Conclusions.