1. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 1 LCLS Undulator Fiducialization

2. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 2 Outline Fiducialization Procedure Capacitor sensors Cam movers Pointed Magnets Test Results Fiducialization Errors Summary

3. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 3 Fiducialization Procedure Goal to find position of undulator axis with respect to mechanical references. Based on results of magnetic measurements. Magnetic measurements, tuning, and fiducialization is one procedure. 1. Alignment to the bench. First step - by conventional tools (±0.2mm); second with the use of capacitor sensors (±10µm). Reference plates for initial alignment to the bench and as capacitor sensor home positions (ordered). Position adjustments with cam movers. 2. Hall probe measurements to find magnetic axis, i.e. magnetic reference (±5µm random error). Final pitch and yaw corrections. 3. Coordinate transfer from magnetic to mechanical references. Pointed magnets as intermediate reference. Offset between magnetic axis and PM center by bench stage encoders. (Probe centering ±1µm in Y and ±3µm in X). Distance from PM center to PM tooling balls is known from PM calibration. CMM for mechanical measurements (±15µm).

4. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 4 Fiducialization Procedure (cont.) Set-up on the bench X,Y,Z Granite table Hall probe Cam movers Pointed Magnets Undulator support Stages

5. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 5 Capacitor sensor fixture 6 HPB-150 Capacitec sensors (amplifier card Model 4100-SL) Macor ceramic rod Goniometer Y-stage G-10 Arm

6. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 6 Capacitor sensor measurements 6 channels Simultaneously A/D Converter IOtech ADC 488 Triggers from Z - Stage encoder Every 200 µm 17000 x 6 data 10 Points - ? window u /2 Start position First minimum Z - positions of minimums and voltages for 4 channels Apply Calibration ~10mV/µm Calculation of X,Y, Roll, Pitch, Yaw. (Gap, cant angle - ?) Make decision Position corrections by cam movers

7. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 7 Cam Mover Design Potentiometer (Novotechnik P6500 Series) Stepper Motor (Compumotor LN Series) Harmonic Drive (1:120) Brake Cam *G. Bowden “Roller Cam Positioners.” LCLS-TN-05-? Bearing

8. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 8 Cam movers

9. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 9 Single Cam Mover test set-up

10. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 10 Single Cam Mover Test Results Cam Resolution ≈ 0.2µm / motor step

11. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 11 Cam Mover system test set-up

12. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 12 Cam Absolute Positioning Nx=100µmy=100µmx=400µmy=400µmx=900µmy=0µmx=0µmy=700µm 1-35-1521-2034-9-37 200 -25215 310-2000-3 410 000-3 500000000 Feedback system : Capacitor sensors or Linear gages at MMF HLS + WPS or BBA in the tunnel Cam Number12345 Cam Offset(750µm nominal)746742738759725 = f(>20 mechanical parameters) x y

13. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 13 Hall probe measurements Scan in X at different Z positions Scan in Y at different Z positions Find undulator center for each Z position. Have a set of points along Z direction. Make linear fit for all points along Z. Make corrections for pitch and yaw angles if necessary. The undulator is aligned to the bench. Apply shims to make trajectory straight and correct phase errors. Scan in Z at different X and Y positions. Calculate K vs. Y and K vs. X. Find where K is nominal. This is the position of the axis. Leave Hall probe in that position. Take readings from stages. Goal is to find the undulator magnetic axis Based on Hall Probe noise and our best experience the accuracy will be ±5µm

14. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 14 Pointed Magnet Fixture Goal: Find distances from magnetic center to tooling balls. Problem: Accuracy of probe centering depends on PM misalignment. Solution: Adequate two-point measurement algorithm. * I. Vasserman Quadrupole magnetic center definition using the hall probe measurement technique. APS-Pub. LS-285, Argonne, 2004 Transfer coordinates from the undulator magnetic axis to mechanical reference

15. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 15 Hall probe centering accuracy Std (in X)= 3µm Starting from random positions (±0.2mm) from center, scan in X and Y. Differences in centering results w.r.t. first scan shown.

16. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 16 Pointed Magnet Calibration A 1,2 = D/2 ± Δy Sentron 2-D XZM12 Hall probe Newport X-Y, model 406, stages with CMA-12CCCL actuators and ESP-300 controller

17. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 17 Calibration Test Results Do centering in one position Rotate fixture at 180 ˚ Do centering in second position Calculate offset Calibration accuracy = 1µm in Y, 3µm in X

18. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 18 Fiducialization Errors Total Fiducialization error includes the following components: Finding undulator magnetic axis ~ 5µm Hall probe centering ~ 1µm Pointed magnet calibration~ 3µm Tooling ball eccentricity = 5µm CMM measurement ~ 15µm Other possible errors ~ ? (10µm) Total: 20 µm * LCLS Parameters Database/Undulator-System (PRD 1.4-001-r3) Fiducialization error budget*: Vertical: 40µm Horizontal: 50µm

19. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 19 Summary Fiducialization procedure has been finalized. Capacitor sensors are ready for measurements (designed, machined, assembled, and tested). Pointed magnets and PM calibration fixture have been developed, fabricated, and tested. Adequate measurement algorithm has been proposed and tested. Cam mover and support system is ready. Fiducialization accuracy is expected to be ~ 20 µm. We are ready to start working with the undulator prototype

20. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 20 End of presentation Thank you!

21. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 21 PM mounting

22. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 22 Two-Point Measurement Algorithm B y = 0

23. Yurii Levashov LCLS Undulator Fiducialization ylevash@slac.stanford.edu October 20, 2005 *Work supported in part by DOE Contract DE-AC02-76SF00515 23 Tolerances * Alignment error budget: Vertical-70µm Horizontal-180µm Longitudinal-1mm Roll-1 mrad Pitch-80µrad Yaw-240µrad Do the best!