1. LCLS LCLS-II Survey & Alignment
International Review for PAL-XFEL Survey & Alignment
May 31, 2011
Catherine LeCocq
SLAC Metrology Department

2. SLAC Site

3. From John Galayda LCLS-II DOE CD-1 Review April 26, 2011
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

4. A Five Step Process Planning Monument Network
Information gathering
- Physics requirements
- Engineering interfaces
- Geodetic aspects
Simulation
Monument Network
Component Fiducialization
Installation
Girder Alignment (if applicable)
Component Alignment
Mapping
Operation Phase
Monitoring (if applicable)
Mapping and re-alignment
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

5. SLAC Instrumentation Primary Instrumentation: Accessories:
Automatic Levels: Leica DNA03
Laser Trackers: FARO Xi (Leica AT401 to be acquired for LCLS-II)
In-house portable wire system 
Accessories:
Bar code rods: 2 meters and 0.6 meters long
Tripods: Brunson heavy stands, Kara portable tooling stands
Survey targets: 1 ½” Corner Cube Reflectors (12 per laser tracker)
Field Data Collectors: Paravant and Allegro 
Additional Equipment:
Total Stations: Leica TC2002 and TDA5005
FARO platinum portable arms (4ft, 8ft, 12ft)
Gyrotheodolites: GYROMAT 2000
Optical Plummet: Wild NL
GPS Receivers: Leica SR-530
Laser Scanner: Z+F Imager 5006
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

6. Software Model Parametric Model Stochastic Model Least Square Solution
l = observation vector
x = unknown (or parameter) vector
Stochastic Model
= variance-covariance matrix
= variance factor
Least Square Solution
Free Net Solution
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

7. LCLS-I UH Network Simulation
Tunnel dimensions: 130 m long, 5 m wide and 2 m high
Floor is 1.0 m below beamline, wall monuments are 0.75 m above beamline, laser tracker set-ups are 0.4 m and 0.6 m above beamline
49 Points – 17 Laser Tracker Set-ups
sD = 30 μm sh = 30 μm / D sv =50 μm /D sdh = 50 μm
W23
sz = 22 μm sx = 47 μm sy =46 μm
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

8. LCLS-I Single Total Station Set-up
Single TC2002 Set-up
sD = 100 μm sh = 50 μm/D sv = 50 μm/D
“Plate15”
sz = 83 μm sx = 108 μm sy = 72 μm
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

9. Monumentation Network
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

10. (with removable spherical target)
UH Monumentation
See ESD Undulator Tunnel Survey Monument Positions
wall monuments
(with removable spherical target)
floor monument 6’
1‘ stay-clear
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

11. LCLS-I UH with LCLS-II Undulators
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

12. Observation Schema Laser Tracker Precision Level Other
Adapt observation scheme tested in simulation to real world
3 triplets per point
Calibrate instrument
Follow observation guidance:
1 triplet = 2 sets of direct and reverse
Precision Level
Loop over floor points
Calibrate instrument and rod
1 shot = average of 3 readings
Other
Total station
Nadir plummet
Gyrotheodolite
Portable wire
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

13. LCLS-I Network for UH Installation
Points
451
Tracker 86
Total Station 11
Triplets
1475
Height Differences
473
Azimuth 14
Wire 3
Horizontal Offsets 79
Point Coordinates
1329
Instrument Coordinates
291
Instrument Rotations
269
Nuisance Parameters 7
Datum Parameters 4
Total Unknowns
1900
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

14. LCLS-I Portable Wire Results
Position [m]
Sigma [µm]
Network measurements alone
Wire measurements included
Coordinate change [µm]
Impact of wire on standard deviations
Impact of wire on coordinates
Network of 393 points with the following observation schema: triplets from 69 tracker setups, 465 height differences and 57 offset measurements to two overlapping wires (240m long and 370m long).
A-priori standard deviations:
Laser Tracker: sD=50 µm, sHz=70 µm/m, sV=100 µm/m
Level: sDh=70 µm
Offset measurement: sDo=30 µm
Extracted from IWAA08 Poster
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

15. Component Fiducialization
Advantage: repeatable references
Methodology: mechanical or magnetic
Tooling Choices: compatible with observation techniques in the field
Instrument:
CMM
Laser tracker
Optical tooling
Robotic arm
Photogrammetry
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

16. Mechanical Fiducialization
LCLS-I Tweeter Quadrupole Magnet
Tooling Ball
FORM
DIAMETER X Y Z
TB 1
TB 2
TB 3
TB 4
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

17. Magnetic Fiducialization
See LCLS-TN-05-11
LCLS-I Undulator
Quadrupole Magnet
Overall fiducialization accuracy in x and y < 25 µm
3 Step Process:
Place wire at quadrupole center: 10 µm
Locate wire: 15 µm
Locate tooling balls: 10 µm
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

18. Undulator Fiducilization
From Zack Wolf & Georg Gassner
LCLS-II DOE CD-1 Review, April 26, 2011
LCLS-I Case: Pointed magnets with same sign poles are added to the ends of the undulator. These magnets have a well defined zero field point in the center. The distance from the measurement axis to the zero field point is determined. A calibration gives the distance from the zero field point to tooling balls on the pointed magnet fixture. The distance from the tooling balls on the pointed magnet fixture to tooling balls on the undulator is measured with a CMM.
LCLS-II Case: More fiducials, independent treatment of the jaws, Measurement with laser trackers. Expected accuracy: 30 to 50 μm
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

19. Girder Alignment Advantages: Variations:
Better relative component alignment
Speed up installation phase
Variations:
Individual component adjustment
Mover Mechanism:
Fixed
Remote
Feedback
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

20. LCLS-I Undulator Girder
Extract from LCLS TN-08-03: Girder Alignment Plan
The Undulator Girder alignment was carried in 2 steps:
Pre alignment and all connection installation (wiring and plumbing in a staging area (see picture above)
Final alignment in a controlled temperature environment on a CMM
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

21. LCLS Coordinate Measuring Machine
Leitz Reference Model CMM manufactured in Wetzlar (Germany)
Weight capacity 3000 kg
Measuring range is 0.9 x 1.5 x 4.5 m
Resolution is 0.1 µm
Spatial accuracy formula in µm based on L, the length measured in mm: L/350.
After specific tuning for the undulator segment weight and location on the CMM, the expected accuracy for the undulator segment should be upgraded to: L/500.
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

22. Component Alignment Timeline: Principle:
Template layout
Stand/base plate alignment
Component/girder alignment
Principle:
Solid monument network
Component fiducialization
Local instrument set-ups
Variations and possible difficulties come with the hardware installed:
Clearance around bolts
Mover system centered around their range
Component pre-set to nominal
Fiducial and mover in-line when possible
Right balance between fine and coarse thread
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

23. Example LCLS-I BTH West
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

24. Mapping Phase Observation scheme: Computation phase: Move list
Identical to monument network
Including component fiducials
Computation phase:
Generating observed position and attitude (and their standard deviations) for each component
Move list
Option 1: to ideal
Option 2: to smooth line
The next 2 graphs show the as-built results for the 33 quadrupole magnets in the Undulator Hall in December 2008, right before the start of LCLS-I.
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

25. LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

26. LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

27. Linac Laser Alignment - Line
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

28. Linac Laser Alignment - Changes
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

29. LCLS-I Measurement Campaigns
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

30. UH Wall Deformations
Both Undulator Hall and X-Ray Tunnel show slow shrinking of the tunnel walls relative to each other by <1mm/year
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

31. Floor Deformations LTU UH XRT FEH Dump FEE NEH
3 mm initial floor deformation, correlated with earth backfill above dump area
Since July 08 deformation < 0.5 mm (~0.5 μm/day for largest deformation)
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,

32. LCLS Survey & Alignment Timeline
Nov 2007
Dec 2007
Jan 2008
Feb 2008
Mar 2008
Apr 2008
May 2008
Jun 2008
Jul 2008
Aug 2008
Sep 2008
Oct 2008
Nov 2008
Dec 2008
Monument
Template
Stand / Plate
Component
Mapping / Move
LCLS-I e-beam Installation
Feb 2004
May 2005
Outside Network
Fiducialization
Girder Assembly
May 2010
May 2011
LCLS-II
LCLS LCLS-II Survey & Alignment
Pohang Accelerator Laboratory,