1. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 1 Georg Gassner Robert Ruland, SLAC February, 2008 Introduction Rotary Table Calibration Laser Tracker Investigation ADM Tests Conclusion Introduction Rotary Table Calibration Laser Tracker Investigation ADM Tests Conclusion Laser Tracker Test Facility at SLAC

2. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 2 Introduction Particle Physics experiments at SLAC require high accuracy positioning, e. g. 100 µm over a distance of 140 m or 25 µm in a 7 x 10 x 3 meter room Realization -> Laser Tracker Measurements Rotary calibration table (Kugler GmbH) providing an accuracy of better than 0.2 arcsec Interferometer bench

3. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 3 Rotary Table Renishaw Signum RESM angle encoder system 1 arcsec graduation accuracy 0.01 arcsec resolution

4. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 4 Calibration of the rotary table (1) Rosette technique calibrate precision polygon prisms sum of the angles measured must result in 360 degrees Moeller-Wedel electronic autocollimator (0.1arcsec accuracy, 0.05arcsec reproducibility)

5. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 5 Calibration of the rotary table (2) Derived Technique set the fixture with the mirrors in a way that mirror ‘a’ is in line with autocollimator ‘a’ rotate the table together with the fixture until mirror ‘b’ is in line with autocollimator ‘b’

6. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 6 Calibration of the rotary table (3) Absolute value of an angle between two positions of the rotary table can be determined with ±0.2 arcsec std.

7. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 7 Laser Tracker Horizontal Angle Measurement System Investigation Test Setup mirror as a target for laser tracker parallelism of the two rotation axes axial displacement of the rotation axes Rotary table Faro Laser Tracker Mirror

8. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 8 Comparison SMR vs. SMM Test of Mirror (SMM) and Retroreflector (SMR) Only small deviations can be found

9. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 9 Calibration Results Two calibration runs with Faro Laser Tracker Xi Two calibration runs with Faro Laser Tracker Xi V2

10. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 10 ADM Calibration on Interferometer Bench Calibration of the scale factor of the ADM in the field. Tests of the general performance and tests to detect malfunctions in the laboratory. Laser Tracker Carriage Interferometer dd Horizontal Bench

11. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 11 Calibration Results Calibration run with Faro Laser Tracker Xi Calibration runs with Faro Laser Tracker Xi V2

12. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 12 Conclusion Rotary table - absolute angle accuracy < 0.2 arcsec Rotary table to test any horizontal angle measurement instrument Faro laser trackers angle measurement system deviations stable and correctible With corrections, angle accuracies of 1 arcsec are possible. Test of the ADM showed its usability as a replacement for the interferometer mode

13. February, 2008 IWAA08 G. Gassner, R. Ruland gassner@slac.stanford.edu 13 End of Presentation