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J.-C. Barri è re

A TLAS Align. PDR J.C. Barri è re (Saclay). P RAXIAL A LIGNMENT S YSTEM (barrel). positioning. Tool for the platform positioning. Platform positioning during MDT construction. QA/QC: in production site and at the CERN X-ray tomograph. J.-C. Barri è re. calibration. calibration of

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J.-C. Barri è re

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  1. ATLAS Align. PDR J.C. Barrière (Saclay) PRAXIAL ALIGNMENT SYSTEM (barrel) positioning Tool for the platform positioning Platform positioning during MDT construction QA/QC: in production site and at the CERN X-ray tomograph J.-C. Barrière calibration calibration of AXIAL part calibration of PRAXIAL part PRAXIAL active optical elements conclusion

  2. ATLAS Align. PDR J.C. Barriere (Saclay) axial Rasnik axial Rasnik 2 proximity Rasniks PRAXIAL ALIGNMENT SYSTEM Principle • The PRAXIAL system is used to unite a layer of chambers (about 6 MDT) • to form a single “rigid” layer. It is composed by two systems: • the axial system (overlapping Rasniks // to beam axis – z –), • the proximity system (2 short crossed Rasniks). • The requirements for the axial are: ±5 mm, • for the proximity system: ±5 mm and ±30 mrad. • The precision on the positioning of both systems are: ± 25 mm MDT- n MDT- n+1 Top view MDT chambers X Z Atlas axis Toroid rib Top view Reference system 3D view

  3. ATLAS Align. PDR J.C. Barrière (Saclay) PRAXIAL ALIGNMENT SYSTEM (barrel) positioning calibration of the PRAXIAL positioning tools final QA/QC with the CERN X-ray tomograph installation of PRAXIAL platforms (on each production site) J.-Ch. Barrière calibration calibration of AXIAL part Principle Calibration of PRAXIAL part

  4. ATLAS Align. PDR J.C. Barrière (Saclay) PRAXIAL ALIGNMENT SYSTEM Caliprax • HARDWARE: • 6 axis motorised table with end-switches, range ± 5 mm, ± 10 mrad. • stiff mechanical structure, • displacement sensors (rasnik/linear encoders) = 1µm, • temperature probes, • 1 PC computer for control and calibration. • SOFTWARE: • ICARAS (rasnik readout), • MINUIT routines (fit), • C++ (general program). • ACCURACY • ± 5 µm, • ± 30 µrad.

  5. ATLAS Align. PDR J.C. Barrière (Saclay) PRAXIAL ALIGNMENT SYSTEM Calibration of proximity part. 1 movement: 2*4 known parameters Masks & CCD: 1 movement: 6 know parameters Lenses: Known with linear encoders 8N > 36 N: number of measurements Measured with praxial rasniks At least 66 movements

  6. ATLAS Align. PDR J.C. Barrière (Saclay) PRAXIAL ALIGNMENT SYSTEM Manual calibration. 1st step: 40 movements for calibration. 2 nd step: 140 movements: 55 pure movements 95 combined movements.

  7. ATLAS Align. PDR J.C. Barrière (Saclay) PRAXIAL ALIGNMENT SYSTEM (barrel) positioning calibration of the PRAXIAL positioning tools final QA/QC with the CERN X-ray tomograph installation of PRAXIAL platforms (on each production site) J.-Ch. Barrière calibration Calibration of AXIAL part Principle Calibration of PRAXIAL part

  8. ATLAS Align. PDR J.C. Barrière (Saclay) PRAXIAL ALIGNMENT SYSTEM Calibration of axial part. 1st STEP (manual operation): Calibration of 3 cubes containing Rasnik elements (mask, Lens, CCD) 7 measurements (X, Y, Q & g ) to control the position of the rasnik elements in the cubes and the bench geometry. 2Dx 2nd STEP: Calibration of the axial elements. One of the cubes is replaced by the axial element to be calibrated. 1 measurement/ axial optical element 5 m long marble

  9. ATLAS Align. PDR J.C. Barrière (Saclay) PRAXIAL ALIGNMENT SYSTEM Conclusion: status & schedule. POSITIONNING & CONTROL TOOLS: The tools are now understood (4*6 positioning tools delivered + control towers). Many error sources are possible. Differential sag between tubes and wires has to be checked. Next X-tomo control end of april 2001 (4 masks delivered). PROXIMITY CALIBRATION (2*1250 units, 6 different gaps): Status: 6 axis motorised tables, endswitches, linear sensors are available. Software is under construction. Mechanical structure is studied Schedule: first calibration in september 2001. AXIAL CALIBRATION: Status: principle of the calibraton has already been tested. Sofware exists and has to be adapted. Schedule: first calibration at end of 2001.

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