Magnetic Measurements For The LCLS Undulator System

Zachary Wolf

LCLS Magnetic Measurements [email protected]

Feb 7, 20071

Magnetic MeasurementsFor The

LCLS Undulator System

Zack Wolf, Yurii Levashov,

Achim Weidemann, Seva Kaplounenko,

Scott Jansson, Ralph Colon, Dave Jensen

Zachary Wolf


Feb 7, 20072

Introduction

The LCLS will consist of 33 undulator segments.The last 1/3 of the linac is used to produce the electron beam.Some Parameters:Ebeam = 13.64 Gevλr = 1.5 ÅPlanar permanent magnet undulatorsNd Fe B permanent magnetsλu = 30 mmGap = 6.8 mmTapered gap, 4.5 mradBfirst = 1.249 T, tapered, nominal field, first undulatorKfirst = 3.5, tapered, each undulator has its own K226 poles per segmentEach segment is 3.4 m long

Zachary Wolf


Feb 7, 20073

LCLS LocationJ. Galayda

Zachary Wolf


Feb 7, 20074

Schedule

AAAA SSSS OOOO NNNN DDDD JJJJ FFFF MMMM AAAA MMMM JJJJ JJJJ AAAA SSSS OOOO NNNN DDDD JJJJ FFFF MMMM AAAA MMMM JJJJ JJJJ

Drive-Drive-Laser Laser

InstalledInstalled

Drive-Laser Drive-Laser Commissioning Commissioning

Gun/Inj./BC1 Gun/Inj./BC1 Commissioning Commissioning

Gun/Inj./BC1 Gun/Inj./BC1 InstallInstall

(8/21 – 2/20)(8/21 – 2/20) linac/BC2 linac/BC2 Install Install

Inj./Linac/BC2 Inj./Linac/BC2 Commissioning Commissioning

LTU/und. LTU/und. Install Install

2006200620062006 2007200720072007

LTU/und.LTU/und.hall “ready”hall “ready”

ControlsControlsCheckouCheckou

t t

LTU/und. LTU/und. Commissioning Commissioning

First Spont. First Spont. LightLight

2008200820082008

Dave Schultz

Zachary Wolf


Feb 7, 20075

Undulator Tuning

Magnetic Measurement Facility

Zachary Wolf


Feb 7, 20076

Magnetic Measurement Facility

Floor plan divided into three functional areasMagnetic Measurements (± 0.1º C)Fiducialization and Assembly (± 1º C)Storage (± 2.5º C)

Test stand lay-out is driven by requirement to match the Earth Magnetic Field conditions in lab to Undulator Hall, i.e. azimuth and gap orientation need to be identical

LCLS-TN-04-1

Zachary Wolf


Feb 7, 20077

Undulator Movements In MMF

1 Week, Come to 20 C

1 Week, Rough Tuning

1 Week, Fine Tuning

<1 Week, FinishFiducialization

Peak Throughput: 1 undulator per week

Tuning Time:about 4 weeks

Zachary Wolf


Feb 7, 20078

MMF Temperature

Achim Weidemann

Time history at the Kugler bench

In general, the system meets stability requirements

Zachary Wolf


Feb 7, 20079

Rough Tuning Bench Components

Zachary Wolf


Feb 7, 200710

Rough Tuning Bench

CamMovers

Cable Handling Bench

UndulatorReference Pole

Zero Gauss Chamber

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Feb 7, 200711

Capacitive Sensor Alignment Performance

Undulator mechanically aligned to bench in 15 minutes

Yurii Levashov

Zachary Wolf


Feb 7, 200712

Scans Begin And End In A Zero Gauss Chamber

Beginningzero fieldmeasurement

Endingzero fieldmeasurement

Senis Hall probe

Zero Offset CorrectionAssume linear offset dependence on time

Zachary Wolf


Feb 7, 200713

Gap Shims

ANL TB-48

Tapered Shim

Zachary Wolf


Feb 7, 200714

X Trajectory Shims

Apply shims to top and bottom poles Shims weaken By, don’t cause Bx Can’t strengthen pole, instead place

shims on next pole to reduce deflection in other direction

Developed software to automate shim placement

ANL/APS/TB-48

LCLS-TN-04-7

ANL/APS/TB-48

Isaac Vasserman’s Ideas

Zachary Wolf


Feb 7, 200715

Y Trajectory Shims

X-field vs. X-position

-0.004

-0.003

-0.002

-0.001

0

0.001

0.002

0.003

0.004

0.015 0.02 0.025 0.03 0.035 0.04

meters

T

Bx ShimNew Design

Smaller external fieldsUniform Bx field in gap

Yurii Levashov

Inconel

SteelSpot weld

OldShim

Design

Zachary Wolf


Feb 7, 200716

Straighten X And Y Trajectories

MeasuredX

Trajectory

CalculateShims

ModeledX TrajWithCalc

Shims

MeasuredX Traj

After CalcShimsApplied

The Shimming Is Automated

Zachary Wolf


Feb 7, 200717

Phase Shims

Measure By with a Hall probe Calculate phase error Calculate shims to correct error Apply shims, repeat

Developed software to automate shim placement

ANL/APS/TB-48LCLS-TN-04-7

We don’t have shims to strengthen a magnet, only weaken Must locally reduce the gap to increase phase shift

Zachary Wolf


Feb 7, 200718

Rough Tuning Test Plan1) Place undulator

Use kinematic mount2) Mechanically align to test stand

Optical alignment check, use capacitive sensors and cam movers3) Magnetically align Hall probe to undulator

Move Hall probe in x and y to magnetic center4) Rough tuning

Tune x and y trajectories, anticipate magnetic shield5) Adjust gap

Measure K, adjust gap to set K to required value for that undulator6) Check alignment

Alignment may have changed from gap adjustment7) Rough tuning

Anticipate magnetic shield8) Add magnetic shield9) Check tuning

Achim Weidemann

Zachary Wolf


Feb 7, 200719

Each Undulator Has Its Own K Value

From Heinz-Dieter Nuhn

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Feb 7, 200720

Fine Tuning Bench Components

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Feb 7, 200721

Fine Tuning Bench

Kugler Bench

Cable Handling

Steel GirderAnd Stands

Cam Movers

UndulatorWith MagneticShield

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Feb 7, 200722

Kugler Bench Performance

Measurements by Georg Gassner

X Y straightness spec: < 14 μmPitch and yaw spec: < 4.2 μrad

Specs met in long block region

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Feb 7, 200723

Coils For Fine Tuning Bench

Field Integral Coil

Short Coil Zero Gauss Chamber

Dave Jensen

Bx, By One Undulator Period Long Coils

I1

I2

Zachary Wolf


Feb 7, 200724

Fine Tuning Test Plan1) Place undulator Use kinematic mount, use steel girder and stands, shield on2) Mechanically align to test stand

Optical alignment check, use capacitive sensors and cam movers3) Magnetically align Hall probe to undulator

Move Hall probe in x and y to magnetic center4) Determine the tuning axis Move in x to where K has the required value5) Tuning Tune x and y trajectories, phase6) Add phase matching shims7) Adjust field integrals Use long coil, I1 and I2 for both Bx and By8) Adjust field uniformity Add quadrupole and sextupole shims as necessary9) Final checks before gluing shims Check x and y trajectory, phase, phase matching, field integrals, uniformity

Yurii Levashov

Zachary Wolf


Feb 7, 200725

Fine Tuning Test Plan (cont.)10) Glue shims in place Remove y trajectory, quadrupole, sextupole, and phase shims, apply glue, replace11) Check the gap

Make sure no parts of a shim protrude into the gap12) Check for errors while gluing shims

Check x and y trajectories, phase, I1 and I2 of Bx and By, uniformity13) Map Bx and By in the retracted position14) Final results data set Measure Bx and By at x = -6, -5, …, 6 mm, y = -0.2, -0.08, 0 0.08, 0.2 mm, calculate field integrals vs z, 65 scans15) Find the x position, y=0, where K has the required value16) Add fiducialization magnets to both ends Measure offsets from beam axis to the center of the fiducialization magnets17) Rough fiducialization using alignment equipment18) Measure roll on flats at each undulator end19) Move undulator to CMM, finish fiducialization

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Feb 7, 200726

Fiducialization, Determine K vs X

K XK0

K vs X

Set the probe position to give the nominal K value.

X0

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Feb 7, 200727

Fiducialization

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Feb 7, 200728

Hall Probe Calibration

SENIS 24-06

-50

-40

-30

-20

-10

0

10

20

30

40

50

-10 -8 -6 -4 -2 0 2 4 6 8 10

Voltage (V)

Fie

ld-0

.2*V

olt

age

(G)

SENIS 24-06

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-10 -8 -6 -4 -2 0 2 4 6 8 10

Voltage (V)

Fie

ld (

T)

ChillerFor probetemperature

Magnet

Water NMR

MetrolabNMR

HP3458

Seva Kaplounenko

Zachary Wolf


Feb 7, 200729

Schedule

Robert Ruland

Zachary Wolf


Feb 7, 200730

Quadrupole Fiducialization System

LCLS-TN-05-11

Zachary Wolf


Feb 7, 200731

Quadrupole FiducializationVibrating Wire Technique

Force On Wire

Move wire until the vibration stops:Quadrupole Center

A. Temnykh, NIM A 399 (1997) 185.

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Feb 7, 200732

Detector Signal vs Quad Position

Zachary Wolf


Feb 7, 200733

Pitch and Yaw Measurements

Zachary Wolf


Feb 7, 200734

Quadrupole FiducializationSchematic System Overview

Wire Vibration Sensor

Wire Finder

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Feb 7, 200735

Conclusion

• MMF construction is complete, temperature stability and set point accuracy requirements have been met• The rough tuning bench is complete• The Hall probe calibration system is complete• The fine tuning bench has all components complete. A stage is being repaired for the long coil system. Afterward, the bench will be complete.• The software is complete. Some automation work and improvements are still being done.• Mechanical alignment takes about 15 minutes.• The fine tuning bench construction meets all specifications.• The expected throughput is one undulator per week. Each undulator, however, spends about 4 weeks in the MMF.• One reference undulator gets re-measured every fourth undulator.• We have begun production undulator tuning.

Documents

Magnetic Measurements For The LCLS Undulator System