DELTA Quadrant Tuning

Y. LevashovE. Reese

Tolerances for prototype quadrant tuning

Magnet center deviations from a nominal center line < ± 50 m in X and <+50 m in Y.

Parameter Assembled Undulator Quadrant

K >3.4853 (Slot 33) >1.2323 (± 110-3 )

Phase error R.M.S. <10° < 3°

First field Integrals < 40 Tm (40 G-cm) < 10 Tm (10 G-cm)

Second field Integrals < 50 Tm2 (5000 G-cm2) < 10 Tm2 (1000 G-cm2)

The undulator can not be tuned when assembled. Each magnet array was tuned individually then mounted on a quadrant actuator plate.

Tuning procedure outlineInitial magnet alignment using CMM to ±50 m from the beam axis. Tuning with iterations based on virtual shimming(re-positioning the magnets w.r.t. magnetic axis).Round 1: - Tune trajectories and phase errors with the use of CMM data.- Measure K- Check magnet positions on CMM.Round 2: - Correct magnet positions to be within ±50 m from the beam line. - Continue tuning trajectories and phase errors with the use of CMM data. - Set K-value as close as possible to the average from Round 1.- Check magnet positions at CMM.Round 3:- Correct magnet positions to be within ±50 m from the beam line. - Do final adjustments to trajectories, phase errors, and K.- Check magnet positions at CMM.Round 4(if necessary)….

CMM measurements

1. Measure dowel pin holes on the bottom. Transfer x – axis on the side of the plate.2. Scan along the curve surface on each magnet, fit circle of 3.2mm radius, for each

magnet find x & y coordinates of the circle center.3. Find deviations of magnet centers from the beam line in x and y.

Dowel pin holes

Set screw forX- adjustments

Shim forY- adjustments

Beam axis

YX

Set-up on measurement bench

Alignment table Thermistors Hall probeGranite block

6 threaded inserts

2 dowel pinholes

Micrometer

Alignment to the bench (X & yaw)

0.012 0.014 0.016 0.018 0.02 0.022 0.024 0.026 0.028 0.030

0.050.1

0.150.2

0.250.3

0.350.4

0.450.5

By vs probe X position

X (m)

B (T

)

1. Do Hall probe scan in X at each pole location2. Truncate data ± 3mm from center3. Fit parabola, find center4. Fit a straight line through all pole centers, find x and yaw, correct yaw if necessary.

Alignment to the bench (Y)

Bottom of the magnet array bottom to beam line = 44.653mm (1.758”)

Fiducialization fixture

Sight level

Granite block

• Find center of fiducialization fixture with the Hall probe• Measure difference in height between the fixture and the granite by optical tools• Set Hall probe Y using bench vertical stage

ΔY = 30μm ΔB/B 1%

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1-2

-1.5

-1

-0.5

0

0.5

1

1.5

2x 10

-6 X Trajectory

X (m

)

Z position (m)

5 18 30 43 55 Pole

Trajectories (#3)

I1Y = -351µTmI2Y = -281µTm2

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1-2

-1.5

-1

-0.5

0

0.5

1

1.5

2x 10

-6 Y Trajectory

Y (m

)

Z position (m)

5 18 30 43 55 Pole

I1X = +738 µTmI2X = +479µTm2

I1Y = +5µTmI2Y = +5µTm2

I1X = +1 µTmI2X = -8 µTm2

-0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5-8

-6

-4

-2

0

2

4

6Phase Error At Field Peaks, No Ends

Pha

se E

rror (

deg)

Z position (m)

5 11 18 24 30 36 43 49 55 Pole

Phase Error: Ave = 0.000000 deg, RMS = 2.278216 deg

Phase Errors (#3)

R.M.S = 40 deg.

R.M.S = 2 deg.

After tuning the trajectories the R.M.S. phase error goes down to 1015 deg. The rest is tuned out by virtual shimming

Tuning resultsDataSet 001

Q1 Q2 Q3 Q4 T 20.2 20.3 20.4 20.2

I1X +7 -8 -2 -11 I2X +2 -2 +6 -14 I1Y -12 +8 -4 +3 I2Y -4 +2 0 +12 K 1.3085 1.2986 1.3322 1.3447

Ph.Err.RMS 3.4 5.0 3.4 3.6 Run # 49 58 70 77

DataSet 002

Q1 Q2 Q3 Q4 T 20.1 20.3 20.2 20.2

I1X -3 -4 +5 -2 I2X +8 0 +3 -3 I1Y +1 0 +2 -4 I2Y 0 -7 +1 +3 K 1.3348 1.3346 1.3347 1.3350

Ph.Err.RMS 2.6 3.1 2.5 3.2 Run # 7 23 26 16

DataSet 003

Q1 Q2 Q3 Q4 T 20.2 20.4 20.3 20.1

I1X -2 -4 +1 +6 I2X +6 -2 -8 +2 I1Y -2 -2 +5 -4 I2Y -6 -8 +5 -1 K 1.3281 1.3297 1.3327 1.3285

Ph.Err.RMS 2.8 3.1 2.3 3.0 Run # 3 6 11 8

(ΔK/K +7%)

Final CMM Measurement results

Maximum deviation from center line is:-69 m in X and +37m in Y

Issues for 3.2m device

• A special fixture is required to allow a quick accurate quadrant set-up on the

measurement bench, magnets facing up.

• The Hall probe has to be set at the same height for all quadrants with accuracy

better than 10m. Optical tools to be replaced by micrometers or Keyence sensor.

• Larger screws for magnet X adjustment.

• A provision to mount a micrometer to control magnet motion.

• Since vacuum chamber has no fins, magnet alignment tolerance in X direction

could be ± 100μm. It will reduce number of iterations.

Current Status

5mm ID, 6.3mm OD copper tube

Hall probes

1.2 m long G-10 rod

• Measurement system for the 1m long prototype is in place and ready.• First measurements done to check the system. • Relative roll angles and displacements are measured for X and Y probes.• Prototype mechanical and controls’ issues to be solved before measurements

continue.

stage

Retro-reflector

Conclusion

•Tuning procedure has been developed for DELTA quadrants.

•Four quadrants have been successfully tuned to tolerances in 12 days (3 days/quadrant).

•Simulations show that the assembled device should meet the tolerances.

•Measurements system for assembled prototype is in place and it’s functionality tested.

•Magnetic measurements are in progress.

Back-up slides

Field superposition, Linear Horizontal

Field superposition, Linear Vertical

Field superposition, Circular left