1. Abstract Mechanical Inspection and Survey Steven Seiler, NSLS-II Project The Survey and Alignment Group is often the first and last to work with the Storage Ring magnets. Surveyors inspect, characterize and pre-align each magnet then later record the final location of each magnet on a girder assembly. This presentation describes the Survey and Alignment work on Storage Ring magnets with emphasis in the magnet’s local coordinate system creation and pre-alignment method. *Work performed under auspices of the United States Department of Energy, under contract DE-AC02- 98CH10886 1

2. 2 Mechanical Inspection & Survey NSLS-II Magnet Workshop Steve Seiler April 11, 2012

3. 3 Outline Girder Inspection Magnet Inspection –Local Coordinate System Creation General Sextupole General Quadrupole Special Quadrupole Magnet Fiducial Discussion Pre-Alignment Environmental Room

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5. 5 Girder Inspection Goals –Verify drawing dimensions are w/in tolerance –Relate Datums to mounting slots and all magnet mounting holes –Create girder reference file

6. 6 Girder Inspection Two Laser Tracker setups w/ girder on stands (to get bottom datum)

7. 7 Magnet Inspection Goals –Verify ICD dimensions are w/in tolerance –Relate mechanical center and orientation to all outside fiducials –Create magnet reference file

8. 8 Top Fiducial Frame Each of the three top fiducials is measured twice using a pin nest and the 1.5” probe –Once with the CMM arm top joint upstream –Once with the CMM arm top joint downstream US/DS points averaged for each fiducial Frame built such that Y is normal to the plane of the three averaged fiducials, Z points from fiducial 2 to 3, and the origin is at fiducial 2.

9. 9 Top Fiducial Frame X Y Z 1 3 2

10. 10 US/DS Fiducial Planes 4 upstream and 3 downstream (most magnets) fiducials define these faces Each fiducial is measured with a pin nest and the 1.5” probe tip The dZ (with the Magnet Frame active) of the two plane centroids is the mechanical yoke length

11. 11 US/DS Fiducial Planes 1 23 4 1 2 3 Upstream Downstream

12. 12 Pole Tips (Sextupole) Space between pole tips measured from upstream and downstream faces Points grouped so that opposite groups form planes –Horizontal (H) –Diagonal 1 (D1) –Diagonal 2 (D2) 6 total planes created: –US: H, D1, D2 –DS: H, D1, D2 H D1D2

13. 13 Pole Planes/Lines (STP) Three lines are created upstream by intersecting each of the upstream planes to each other: –US H / US D1 –US H / US D2 –US D1 / US D2 Same for downstream planes Points created at each line’s endpoints

14. 14 Z Axis (STP) 2 plane intersection line endpoints US PlaneDS Plane US AVG LINE DS AVG LINE US DS US DS US DS USDS Z AXIS (Side View)

15. 15 Pole Tips (Quadrupole) Space between pole tips measured from upstream and downstream faces Points grouped so that opposite groups form planes –Horizontal (H) –Vertical (V) 4 total planes created: –US: H, V –DS: H, V H V

16. 16 Pole Planes/Lines (Quad) Line created upstream by intersecting the upstream planes to each other: –US H / US V Same for downstream planes Points created at each line’s endpoints

17. 17 Z Axis (Quad) 2 plane (H & V) intersection line endpoints US PlaneDS Plane US AVG LINE DS AVG LINE US DS US DS US DS USDS Z AXIS (Side View)

18. 18 Pole Tips (Special Quad) Space between pole tips measured from upstream and downstream faces Points grouped so that opposite groups form plane –Horizontal (H) H Spacer Bars prevent vertical plane from being measured Lines fit to Beam Left and Beam Right points

19. 19 Pole Planes/Lines (Special Quad) Lines created through points measured between poles (horizontal plane) Points created where these lines intersect the upstream and downstream fiducial planes Points averaged to create endpoints for Z axis

20. 20 Z Axis (Special Quad) US PlaneDS Plane BL DS USDS Z AXIS (Top View) US BLDS US BLUS DS BLDS DS BLUS BL US BL DS LINE BL US LINE BR DS US BRDS US BRUS DS BRDS DS BRUS BR US BR DS LINE BR US LINE PLANE LINE Lines fit through measured points on Horizontal Plane Horizontal Plane

21. 21 Temporary Magnet Frame Sextupoles and General Quadrupoles: –Origin at midpoint of Z AXIS line –Primary axis: Z AXIS line defines +Z –Secondary axis: US Horizontal plane normal defines +Y –“TEMP” frame has correct Z axis, but incorrect roll (only based on 1 pole plane out of 4 or 6) Special Quadrupoles: –Mechanical Frame made directly, no need for “TEMP” Frame –Origin at midpoint of Z AXIS line –Primary axis: Z AXIS line defines +Z –Secondary axis: Normal direction of plane fit through four points BL US, BL DS, BR US, BR DS (Intersections of BL and BR lines with US and DS planes)

22. 22 Magnet Frame Sextupole: Rotate “TEMP” Frame to account for other 5 pole planes –US D1, US D2, DS H, DS D1, DS D2 Normalize each individual deviation from nominal (divide by 6) Add together normalized deviations and apply this rotation (Rz) to “TEMP” to create “MECHANICAL” frame Quadrupole: Rotate “TEMP” Frame to account for other 3 pole planes –US V, DS H, DS V Normalize each individual deviation from nominal (divide by 4) Add together normalized deviations and apply this rotation (Rz) to “TEMP” to create “MECHANICAL” frame

23. 23 Roll Mechanical roll that is reported is the relationship (Rz) of the Top Fiducial Frame and the Magnet Frame. Top fiducials, US/DS fiducials, and pole tips are measured within a loop. The user determines how many times to iterate the loop and an average Top Fiducial Frame and Magnet Frame is produced as well as a Magnet Frame and roll for each iteration.

24. 24 Magnet Inspection Data

25. 25 Fiducial Considerations Repeatability –Variation of position under the same conditions –Test: Fiducial position in different iterations of magnet inspection Most repeatable component (<10 μm) corresponds to banking surface. Up to 30 μm error from pin nest fit.

26. 26 Fiducial Considerations Reproducibility –Variation of position under different conditions –Test: Best fit of magnet fiducials measured with LT to CMM arm inspection file

27. 27 Fiducial Type Repeatability, durability, cost Requires pin nest One less interface

28. 28 Pre-Alignment Goals –Create ideal reference file of populated girder –Use two Laser Trackers to position magnets –Coarsely position magnets in X and Y (~100μm) –Insert and position vacuum chamber

29. 29 Pre-Alignment Setup Two granite blocks & 4 posts w/ control points Girder stops positioned in line with girder datums Vibrating wire position in Environmental Room is known relative to girder banking surfaces and control points in P-A Stops

30. 30 Pre-Alignment Method Hamar Laser –Mechanical X, Y, Pitch, Yaw –Roll from level magnet tops, Z from laser tracker Laser Tracker(s) –Mechanical X, Y, Z, Pitch, Yaw –Magnetic Roll (Requires reliable magnetic data related to fiducials) –Vacuum chamber aligned to magnet centers

31. 31 Environmental Room Goals –Complete final alignment of magnets relative to girder –Record offsets of individual magnets relative to ideal position on girder –Create aligned reference file Stops

32. 32 Typical ER Procedure Pre-aligned, populated girder is moved to the ER Girder is banked against stops replicating the P-A setup Laser trackers (4 positions) are used to locate Vacuum Chamber BPM positions relative to the wire V-notches First run of vibrating wire shows best fit line & deviations Magnets are moved close to the BPM line and re- measured Final offsets of magnets are recorded with vibrating wire measurement Reference of final conditions recorded by 12 laser tracker positions

33. 33 Aligned Reference File 12 Laser Tracker positions record all girder and magnet fiducials as well as all control in the Environmental Room

34. 34 Environmental Room Data ΔX, ΔY –From vibrating wire ΔZ –From LT observations on magnet fiducials Roll, Pitch, Yaw –From LT observations on magnet fiducials

35. 35 Typical ER Uncertainty Inter-Fiducial Distance Combined 2 Fiducial Uncertainty =√(U 1 2 +U 2 2 ) Estimated Angular Uncertainty Roll

36. 36 End