VISAFiducialization and AlignmentR. Ruland, B. Fuss, Z. Wolf, D. Arnett, G. Bowden, R. Carr,B. Dix and C. Le Cocq, SLAC

G. Rakowsky, J. Aspenleiter, J. SkaritkaBNLPresented by Brian Fuss

TasksFiducializationRelate fiducials to magnetic centerlineAlignmentPosition undulator magnets with respect to each other Reference Laser BeamSetup RLB with respect to undulator position

Alignment Error Budget

[m]

Magnetic Centerline Determination

20

Transfer onto Fiducials

23

Positioning

28

Setup RLB with respect to Undulators

29

Total (added in quadrature)

51

First TaskFiducializationRelate fiducials to magnetic centerline

Fiducialization Procedural StepsPosition wire to represent magnetic centerlineDetect wire with Wire Finders and reference wire position to mechanical fiducials (metric measurement)Measure WF and undulator fiducials with respect to straight line using SI (relative measurements)Calculate undulator fiducial offsets using a similarity transformationRepeat above steps with undulators rolled in 90 incrementsCheck closure

Fiducialization: Step 2Wire Finder DesignA PSD detects light from a laser diode which is aperture limited by a slit. Slit width is a fraction of wire diameter. Detector assembly scans across wire. PSD response clearly indicates wire edges.

Fiducialization: Step 2 Wire Finder MeasurementsMeasuring wire positionDetector assembly is driven across wire profile. Micrometer readings are recorded at two defined detector voltage output levels on either side of the wire. The mean of the micrometer readings yields the wire center position.

Chart2

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2580

Horizontal Position [m]

Diode Current [mVolt]

Wire Finder Calibration Curve

Sheet1

0462.5462.525302560462.5-462.52560

12.5450450.025302560450.0-450.02560

25437.5437.525302560437.5-437.52560

37.5425425.025302560425.0-425.02560

50412.5412.525202540412.5-412.52540

62.5400400.025202540400.0-400.02540

75387.5387.525202540387.5-387.52540

87.5375375.025202540375.0-375.02540

100362.5362.525302560362.5-362.52560

112.5350350.025302560350.0-350.02560

125337.5337.525302560337.5-337.52560

137.5325325.025202540325.0-325.02540

150312.5312.525202540312.5-312.52540

162.5300300.025602620300.0-300.02620

175287.5287.526002700287.5-287.52690

187.5275275.025502600275.0-275.02690

200262.5262.524902480262.5-262.52600

212.5250250.024502400250.0-250.02460

225237.5237.524802460237.5-237.52400

237.5225225.025302560225.0-225.02450

250212.5212.526202740212.5-212.52560

262.5200200.027102920200.0-200.02740

275187.5187.527152930187.5-187.52920

287.5175175.027803060175.0-175.03060

300162.5162.528303160162.5-162.53160

312.5150150.028303160150.0-150.03160

325137.5137.527603020137.5-137.53020

337.5125125.026202740125.0-125.02740

350112.5112.524102320112.5-112.52320

362.5100100.021801860100.0-100.01860

37587.587.51930136087.5-87.51360

387.57575.01750100075.0-75.01000

40062.562.5163076062.5-62.5760

412.55050.0158066050.0-50.0660

42537.537.5157064037.5-37.5655

437.52525.0159068025.0-25.0680

45012.512.5161072012.5-12.5740

462.500.016407800.00.0770

475-12.5-12.51620740-12.512.5750

487.5-25-251610720-2525.0715

500-37.5-37.51580660-37.537.5660

512.5-50-501585670-5050.0660

525-62.5-62.51605710-62.562.5730

537.5-75-751705910-7575.0910

550-87.5-87.519001300-87.587.51300

562.5-100-10021501800-100100.01800

575-112.5-112.523802260-112.5112.52260

587.5-125-12526002700-125125.02700

600-137.5-137.527503000-137.5137.53000

612.5-150-15028203140-150150.03140

625-162.5-162.528203140-162.5162.53140

637.5-175-17527903080-175175.03080

650-187.5-187.527202940-187.5187.52940

662.5-200-20026402780-200200.02780

675-212.5-212.525802660-212.5212.52640

687.5-225-22524902480-225225.02480

700-237.5-237.524602420-237.5237.52420

712.5-250-25024702440-250250.02440

725-262.5-262.525402580-262.5262.52580

737.5-275-27525902680-275275.02680

750-287.5-287.526002700-287.5287.52700

762.5-300-30025802660-300300.02660

775-312.5-312.525402580-312.5312.52580

787.5-325-32525302560-325325.02560

800-337.5-337.525352570-337.5337.52570

812.5-350-35025452590-350350.02590

825-362.5-362.525452590-362.5362.52590

837.5-375-37525402580-375375.02580

850-387.5-387.525402580-387.5387.52580

862.5-400-40025402580-400400.02580

875-412.5-412.525402580-412.5412.52580

887.5-425-42525452590-425425.02590

900-437.5-437.525402580-437.5437.52580

912.5-450-45025402580-450450.02580

-462.525402580-462.5462.52580

Sheet2

Sheet3

Fiducialization: Step 2Wire Finder Implementation

Fiducialization: Step 2Wire Finder CalibrationObjective:Calibration relates wire position measurements to reference fiducialPrinciple:Distance between fiducials known. Wire position is determined two times but with WF yawed 180 after 1st measurement

Fiducialization: Step 2Wire Finder CalibrationFrom these two wire measurements we obtain AI and AII; these are all the parameters needed to calculate calibration offset

Fiducialization: Step 2Wire Finder CalibrationCalibration Example

1st Cal 4_15

Laser Wire Finder Calibration Procedure

Golden Fixture

Operator:Time:Date:

Goal:Determine calibration offset (center of slit relative to reference

tooling ball when micrometer reads zero).

Procedure:

1)Enter L, the distance between the centers of the tooling balls A

and B, as determined on the CMM.

101.135250.5676

2)Set units: push toggle button until read-out shows millimeter.

3)Set Wire finder on calibration mount with reference tooling ball in cup.

4)Reset micrometer: drive cross slide against reference stop, press reset.

5)Find the wire position relative to the micrometer by finding the wire edges

at the 200mV and 400 mV signal level.

6.3376.512

6.3366.512

6.3366.513

6.33636.5123

6.4243

6.3646.489

6.3346.49

6.3646.489

6.35406.4893

6.4217

6.4230

6)Rotate the Wire Finder by 180 around its vertical axis

7)Find the wire position relative to the micrometer again

8.2468.07

8.2458.071

8.2468.071

8.24578.0707

8.1582

8.2238.097

8.2238.097

8.2238.098

8.22308.0973

8.1602

8.1592

8)

43.2765

&L&F &A&R&D &T

2nd Cal 4_15

Laser Wire Finder Calibration Procedure

Golden Fixture

Operator:Time:Date:

Goal:Determine calibration offset (center of slit relative to reference

tooling ball when micrometer reads zero).

Procedure:

1)Enter L, the distance between the centers of the tooling balls A

and B, as determined on the CMM.

101.135250.5676

2)Set units: push toggle button until read-out shows millimeter.

3)Set Wire finder on calibration mount with reference tooling ball in cup.

4)Reset micrometer: drive cross slide against reference stop, press reset.

5)Find the wire position relative to the micrometer by finding the wire edges

at the 200mV and 400 mV signal level.

6.3376.513

6.3376.513

6.3376.513

6.33706.5130

6.4250

6.3646.49

6.3656.49

6.3656.489

6.36476.4897

6.4272

6.4261

6)Rotate the Wire Finder by 180 around its vertical axis

7)Find the wire position relative to the micrometer again

8.0868.261

8.0868.26

8.0858.26

8.08578.2603

8.1730

8.1128.236

8.1128.237

8.1128.236

8.11208.2363

8.1742

8.1736

8)

43.2678

&L&F &A&R&D &T

3rd Cal 4_15

Laser Wire Finder Calibration Procedure

Golden Fixture

Operator:Time:Date:

Goal:Determine calibration offset (center of slit relative to reference

tooling ball when micrometer reads zero).

Procedure:

1)Enter L, the distance between the centers of the tooling balls A

and B, as determined on the CMM.

101.135250.5676

2)Set units: push toggle button until read-out shows millimeter.

3)Set Wire finder on calibration mount with reference tooling ball in cup.

4)Reset micrometer: drive cross slide against reference stop, press reset.

5)Find the wire position relative to the micrometer by finding the wire edges

at the 200mV and 400 mV signal level.

6.336.507

6.336.507

6.3316.507

6.33036.5070

6.4187

6.3576.482

6.3576.482

6.3586.482

6.35736.4820

6.4197

6.4192

6)Rotate the Wire Finder by 180 around its vertical axis

7)Find the wire position relative to the micrometer again

8.0868.26

8.0868.26

8.0868.26

8.08608.2600

8.1730

8.1128.236

8.1128.236

8.1128.236

8.11208.2360

8.1740

8.1735

8)

43.2713

&L&F &A&R&D &T

4th Cal 4_15

Laser Wire Finder Calibration Procedure

Golden Fixture

Operator:Time:Date:

Goal:Determine calibration offset (center of reference

tooling ball to micrometer zero).

Procedure:

1)Enter L, the distance between the centers of the tooling balls A

and B, as determined on the CMM.

101.135250.5676

2)Set units: push toggle button until read-out shows millimeter.

3)Set Wire finder on calibration mount with reference tooling ball in cup.

4)Reset micrometer: drive cross slide against reference stop, press reset.

5)Find the wire position relative to the micrometer by finding the wire edges

at the 200mV and 400 mV signal level.

6.3286.505

6.3286.504

6.3286.505

6.32806.5047

6.4163

6.3556.479

6.3556.48

6.3556.479

6.35506.4793

6.4172

6.4168

6)Rotate the Wire Finder by 180 around its vertical axis

7)Find the wire position relative to the micrometer again

8.0878.261

8.0868.261

8.0868.261

8.08638.2610

8.1737

8.1118.236

8.1128.236

8.1118.236

8.11138.2360

8.1737

8.1737

8)

43.2724

&L&F &A&R&D &T

&L&F &A&R&D &T

5th Cal 4_16

Laser Wire Finder Calibration Procedure

Golden Fixture

Operator:Time:Date:

Goal:Determine calibration offset (center of slit relative to reference

tooling ball when micrometer reads zero).

Procedure:

1)Enter L, the distance between the centers of the tooling balls A

and B, as determined on the CMM.

101.135250.5676

2)Set units: push toggle button until read-out shows millimeter.

3)Set Wire finder on calibration mount with reference tooling ball in cup.

4)Reset micrometer: drive cross slide against reference stop, press reset.

5)Find the wire position relative to the micrometer by finding the wire edges

at the 200mV and 400 mV signal level.

6.3256.502

6.3256.503

6.3256.502

6.32506.5023

6.4137

6.3516.477

6.3516.47

6.3516.477

6.35106.4747

6.4128

6.4133

6)Rotate the Wire Finder by 180 around its vertical axis

7)Find the wire position relative to the micrometer again

8.0848.258

8.0838.258

8.0848.258

8.08378.2580

8.1708

8.118.235

8.118.234

8.118.234

8.11008.2343

8.1722

8.1715

8)

43.2752

&L&F &A&R&D &T

Fiducialization: Step 2Wire Finder RepeatabilityBoth Wire Finders were calibrated four times each in the morning before a fiducialization run and after the run in late afternoon.

Sheet1

Laser Finder Calibration Comparison

Golden FixtureBlack Fixture

beforeDafterDbeforeDafterD

43.2745-0.00343.27420.00043.40170.00043.40380.0000.000150.0000000225

43.26980.00243.2752-0.00143.4035-0.00243.4057-0.002-0.001650.0000027225

43.27130.00143.27290.00243.40060.00143.40250.0010.001250.0000015625

43.2724-0.00043.2758-0.00143.40160.00043.40380.0000.000250.0000000625

0.000150.0000000225

43.27243.27543.40243.404-0.001750.0000030625

-0.003-0.0020.001450.0000021025

0.000150.0000000225

StD.1.5mStD.1.2m0.00000958

0.0011698596

&L&F.xls&R&D &T

Sheet2

Sheet3

Fiducialization: Step 3 Measure fiducials w/r to straight line Requested straightness tolerance excludes standard surveying methodsStraightness interferometry method of choiceStraightness Interferometer cannot measure directly w/r to fiducialsInterface between fiducials and Wollaston prism provided by constant length rod

Fiducialization: Step 3 ArcingRod needs to be placed perpendicular to SI reference lineNot a new problem, typical to optical tooling measurementsSolution: arcing (best-fit circle)

Fiducialization: Step 3 Arcing

Fiducialization: Step 4 Calculate fiducial offsetsAll information now available to calculate the undulator fiducial offsets

Fiducialization: Step 4 Repeatability, DataSteps one through four were repeated four times; to guarantee independent measurements, the undulators and the SI reference line were moved after each iteration

Sheet1

Wire (Magnetic Axis)Interferometer Readings1.5

xyuv4.6

050.53300.2981.5

222350.50322230.92931.1

169.000008288750.53572573071690.351

1134.000081845450.639456674211340.74182.3

1162.000049341250.526027214511620.6367

2129.00009157450.524163200821290.9225

Wire (Magnetic Axis)Interferometer Readings

xyuv

050.5320-0.3343

222350.50122230.2683

169.000008327150.5371315786169-0.281

1134.000064925850.649818704111340.0551

1162.000046003250.52780647671162-0.0073

2129.000084022850.523391900921290.2639

Measurement 1Measurement 2Measurement 3Measurement 4Average

M1_TB450.53650.53750.53550.53850.537

Wire (Magnetic Axis)Interferometer ReadingsM1_TB850.63950.65050.64150.64450.644

xyuvM2_TB450.52650.52850.52450.52650.526

050.53401.9019M2_TB850.52450.52350.52250.52450.523

222350.50422232.5144

169.000007363650.53505497051691.9518DDDD

1134.00007841950.641446957911342.3371M1_TB40.84-0.561.51-1.796.5347

1162.000045688150.524154295211622.2279M1_TB84.29-6.262.30-0.3362.9001

2129.000085416450.521868239321292.5051M2_TB4-0.09-1.871.790.166.7066

M2_TB8-0.710.061.59-0.943.9127

Wire (Magnetic Axis)Interferometer Readings2.3102

xyuv

050.5320-0.0784

222350.50122230.5409

169.000009092250.5383619878169-0.0226

1134.000081304850.644068010111340.3654

1162.000047898950.52577710211620.2553

2129.000088871150.524398063621290.5368

Sheet2

WireInterferometer

(Magnetic Axis)Readings

zyuv

WF_G050.53300.298

WF_B222350.50322230.9293

M1_TB41690.351

M1_TB811340.7418

M2_TB411620.6367

M2_TB821290.9225

WF_G050.5320-0.3343

WF_B222350.50122230.2683

M1_TB4169-0.281

M1_TB811340.0551

M2_TB41162-0.0073

M2_TB821290.2639

WF_G050.53401.9019

WF_B222350.50422232.5144

M1_TB41691.9518

M1_TB811342.3371

M2_TB411622.2279

M2_TB821292.5051

WF_G050.5320-0.0784

WF_B222350.50122230.5409

M1_TB4169-0.0226

M1_TB811340.3654

M2_TB411620.2553

M2_TB821290.5368

Sheet3

Fiducialization: Step 4 Repeatability, ResultsAll but two of the 16 individual measurements agree to within 2 m compared to the respective mean. Standard deviation of all measurements is 2.3 m.

Sheet1

Wire (Magnetic Axis)Interferometer Readings1.5

xyuv4.6

050.53300.2981.5

222350.50322230.92931.1

169.000008288750.53572573071690.351

1134.000081845450.639456674211340.74182.3

1162.000049341250.526027214511620.6367

2129.00009157450.524163200821290.9225

Wire (Magnetic Axis)Interferometer Readings

xyuv

050.5320-0.3343

222350.50122230.2683

169.000008327150.5371315786169-0.281

1134.000064925850.649818704111340.0551

1162.000046003250.52780647671162-0.0073

2129.000084022850.523391900921290.2639

Measurement 1Measurement 2Measurement 3Measurement 4Average

M1_TB450.53650.53750.53550.53850.537

Wire (Magnetic Axis)Interferometer ReadingsM1_TB850.63950.65050.64150.64450.644

xyuvM2_TB450.52650.52850.52450.52650.526

050.53401.9019M2_TB850.52450.52350.52250.52450.523

222350.50422232.5144

169.000007363650.53505497051691.9518DDDD

1134.00007841950.641446957911342.3371M1_TB40.84-0.561.51-1.796.5347

1162.000045688150.524154295211622.2279M1_TB84.29-6.262.30-0.3362.9001

2129.000085416450.521868239321292.5051M2_TB4-0.09-1.871.790.166.7066

M2_TB8-0.710.061.59-0.943.9127

Wire (Magnetic Axis)Interferometer Readings2.3102

xyuv

050.5320-0.0784

222350.50122230.5409

169.000009092250.5383619878169-0.0226

1134.000081304850.644068010111340.3654

1162.000047898950.52577710211620.2553

2129.000088871150.524398063621290.5368

Sheet2

WireInterferometer

(Magnetic Axis)Readings

zyuv

WF_G050.53300.298

WF_B222350.50322230.9293

M1_TB41690.351

M1_TB811340.7418

M2_TB411620.6367

M2_TB821290.9225

WF_G050.5320-0.3343

WF_B222350.50122230.2683

M1_TB4169-0.281

M1_TB811340.0551

M2_TB41162-0.0073

M2_TB821290.2639

WF_G050.53401.9019

WF_B222350.50422232.5144

M1_TB41691.9518

M1_TB811342.3371

M2_TB411622.2279

M2_TB821292.5051

WF_G050.5320-0.0784

WF_B222350.50122230.5409

M1_TB4169-0.0226

M1_TB811340.3654

M2_TB411620.2553

M2_TB821290.5368

Sheet3

Fiducialization: Step 5 Repeat in other roll orientationTo avoid first order errors, all measurements are recorded in the principal planes, i.e. TB on the side is used for horizontal measurements, TB on the top for vertical measurements onlyHence, all fiducialization measurements are one-dimensional plus distance along beamTo determine second dimension, undulator is rolled by 90, and above measurements are repeated

Fiducialization: Step 6 Closure CheckTo check for systematic errors, the undulators are also measured in their 180 and 270 positionsAdding the fiducial offsets of opposing TBs should equal the spatial distance between the two TBs as previously measured on high accuracy CMM

Fiducialization: Step 6 Closure DataUndulator one and two as a pair were used to commission the fiducialization set-up. Several closure measurements are available

Sheet1

[mm][mm]

Magnet 01

TB01_TB04101.129846101.12525

TB05_TB08101.157786101.1780-20

Magnet 02

TB01_TB04101.152198101.1570-5

TB05_TB08101.208586101.2279-19

Magnet 01

TB01_TB04101.1298101.1488-19

TB05_TB08101.1743101.163011

Magnet 02

TB01_TB04101.1522101.132819

TB05_TB08101.1593101.2079-49

M01_TB01101.129846

101.1298460

M01_TB04101.1252

101.1488-24

M01_TB05101.2086

101.159349

M01_TB08101.1780

101.163015

M02_TB01101.1522

101.15220

M02_TB04101.1570

101.14888

M02_TB05101.2086

101.159349

M02_TB08101.2279

101.207920

Sheet2

Sheet3

Fiducialization: Step 6 Closure DataAnother check is provided by comparing fiducial offsets from different iterations

Sheet1

[mm][mm]

Magnet 01

TB01_TB04101.1298101.12525

TB05_TB08101.1578101.1780-20

Magnet 02

TB01_TB04101.1522101.1570-5

TB05_TB08101.2086101.2279-19

Magnet 01

TB01_TB04101.1298101.1488-19

TB05_TB08101.1743101.163011

Magnet 02

TB01_TB04101.1522101.132819

TB05_TB08101.1593101.2079-49

UD

[mm]

M01_TB01101.1298

101.12980

M01_TB04101.1252

101.1488-24

M01_TB05101.1578

101.1743-17

M01_TB08101.1780

101.163015

M02_TB01101.1522

101.15220

M02_TB04101.1570

101.14888

M02_TB05101.2086

101.159349

M02_TB08101.2279

101.207920

Sheet2

Sheet3

Second TaskAlignmentPosition undulator magnets with respect to each other inside the vacuum chamber

AlignmentPhilosophyAlignment step uses analogous approach to fiducialization measurements: straightness interferometry. To permit simultaneous measurement of both dimensions, two straightness interferometers are used

AlignmentProcedural StepsConventional alignment techniques are used to support installation and to achieve global alignment in the beam line coordinate systemDual interferometer system is used to map the undulators positionsFit a straight line & apply similarity transformation to data such that necessary position corrections are minimized and magnetic centers are at nominal positions (i.e., follow a RLB)Apply position corrections under control of interferometersIterate if necessaryQuality Control, re-map undulators; include Laser Finder in both upstream and downstream positions

Alignment: Step 1Conventional AlignmentRoutine work, should yield 100 to 150 mm type position accuracy relative to beam line coordinate system

Alignment: Step 2Dual Interferometer SystemTest measurements showed that it would be desirable to adjust the position of the undulators under simultaneous horizontal and vertical control: hence dual systemSpecial jig was designed to facilitate the set-up of both straightness interferometersJig should be bucked-in w/r to beam line to about 0.5 mm (conventional alignment)

Alignment: Step 2Dual Interferometer System

Alignment: Step 2Dual Interferometer System

Alignment: Step 2Dual Interferometer System

Alignment: Steps 2 - 5Mapping Undulator FiducialsFiducials are mapped analogously to the technique described before for the fiducialization measurements. A full map of horizontal and vertical measurements takes about one hourOn-line data flow and custom programming allows automatic measuring and data analysisStraight line fit optimized to minimize position correctionsYields position corrections for undulators which are expressed in fractions of rotations of the adjustment screwsRe-map, check, iterate if necessary

Alignment: Step 6Quality ControlProduce final map including the fiducial positions of the Laser Finder in its upstream and downstream position

See Poster:Very High Precision Alignment of Undulator Magnets in a Vacuum Chamber

for details on these alignment steps

Third TaskReference Laser BeamSetup RLB with respect to undulator position

Reference Laser BeamPurposeAn optical diagnostics system is integrated into the system design which will aid in steering the electron beam to coincide with the photon beamA laser beam is used to reference the diagnostic system to the undulator axisTherefore the laser beam needs to be pointed such that it coincides with the axis of the undulator assemblyInitially a green laser is used which will be replaced with an infra-red (invisible) laser for final operations A Laser Finder has been designed to relate the optical beam to mechanical fiducials

Reference Laser BeamLaser Finder PrincipleThe LF consists of a frame which carries tooling balls in the same geometry and dimensions as they are mounted to the undulatorA quadrant detector is mounted on a two-dimensional cross-slide centered to the frameThe quadrant detector is used as nulling device. The laser intensity readings are detected on each of two halves of the QD and compared; this arrangement is then electronically rotated by 90 to measure the other dimension

Reference Laser BeamLaser Finder Implementation

Reference Laser BeamLaser Finder CalibrationThe detectors coordinate system needs to be related to the reference tooling ball by a calibration measurementCalibration is performed analogously to the Wire Finder

Reference Laser BeamLaser Finder Calibration

Sheet1

Laser Finder Calibration Procedure

Operator

DateTime

1)Put the detector in the standard configuration:

2)

3)Move the stages until the computer readout shows the beam

is at x = 0, y = 0. Record the micrometer readings.

2.3565mm

4.5763mm

4)Flip the detector over

5)Move the stages until the computer readout shows the beam

is at x = 0, y = 0. Record the micrometer readings.

3.5467mm

2.4365mm

6)Compute the calibration constants:

=47.1839mm

=3.5064mm

Sheet2

Sheet3

MBD00075179.unknown

MBD001B6808.unknown

Reference Laser BeamLaser Finder Buck-in ProcedureThe position of the LF in both its upstream and downstream kinematic mount is known from quality control mappingBased on these parameters, the nominal LF readings for both positions can be calculatedFirst, the beam is pointed such that the LF, preset to the nominal micrometer readings in the downstream position, detects the beam at the center of the QDSecond, the laser is translated, horizontally and vertically, in the upstream position such that the LF, preset to the nominal micrometer readings, detects the beam at the center of the QDThird, the last two steps are iterated until the corrections become insignificant

The End