zachary wolf lcls undulator [email protected] october 30, 2007 1 lcls undulator tuning...

25
Zachary Wolf LCLS Undulator Tuning [email protected]. edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim Weidemann, Seva Kaplounenko, Scott Jansson, Ralph Colon, Dave Jensen, Scott Anderson

Post on 22-Dec-2015

216 views

Category:

Documents


1 download

TRANSCRIPT

Page 1: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 20071

LCLS Undulator TuningAnd Fiducialization

Zack Wolf, Yurii Levashov,

Achim Weidemann, Seva Kaplounenko,

Scott Jansson, Ralph Colon,

Dave Jensen, Scott Anderson

Page 2: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 20072

Progress Since Last FAC

ProgressWe have 15 undulators tuned and fiducialized.The MMF temperature control is working well.The reference undulator measurements repeat within spec.The Hall probe calibrations are stable.The Hall probe reference magnet measurements are stable.A study of the stainless steel beam pipe and steel support was made.A study of undulator mounting effects is under way.The undulator quadrupole fiducialization system was commissioned.

ChallengesNow we need to set K to a specified value. Can’t re-assign slot number.Bad bolts.Machining accuracy of tapered shims.The rough tuning is taking longer than expected.New air compressor still not installed.

Page 3: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 20073

Hall Probe Calibrations In Fixed Mount

Measurements are made in a reference magnet beforethe final data set is taken.

The Hall probe iscalibrated in the same mount it isused in.

Page 4: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 20074

Reference Undulator, Reference Magnet

within spec

temperature?need more studies

taken during referenceundulator measurements

change probemount

(4 undulators tuned,will re-measure)

Y. Levashov

Page 5: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 20075

SchedulePresent Status:15 undulators tuned and fiducialized2 in fine tuning1 in rough tuning2 deferred for major re-work (bad end magnets, large sag might hit beam pipe) (minor problems like bad bolts or requiring gap shim replacement are fixed as we go)

Present Schedule:17 tuned and fiducialized1 tuned

We are 2 to 4 weeks behind schedule (which is 6 months ahead of installation).

Page 6: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 20076

Actions To Help The ScheduleProblemsRough tuning is taking a long timeDifficult to set K to a specified value (can no longer just re-assign slots)Need to replace bad boltsNeed to replace many gap shims (±50 micron strongback tolerance, ±20 micron shim range)Problems with large tapered shim dimension deviations (need to measure shim removed and measure shim replaced)Need to set gap to 4 microns (!) for beam axis to be within ±1 mm of magnetic center (±2 mm good field region) SolutionsNew gap shimming standMeasure size of removed shim and size of replacement shimUse capacitive sensors for rapid feedbackKugler bench assists with rough tuning when requiredCoordinate technicians time better (start shimming at 7am)Set K and do phase shimming in one step

Page 7: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 20077

Phase Relative To A Reference WaveIs Used To Set Gap And Do Phase Shimming

measurementrequires alignment ofundulator andprobe

need phasematching shim,not a problem

problem

problem

problem

after an iteration

Page 8: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 20078

Gap Shim, Capacitive Sensor Feedback

check gapshimming withcapacitivesensors

fast,doesn’trequire muchalignment

errorerror

error

shims werereplaced atthe error locations

the removedshims wereundersize,the replacedshims wereoversize

can catch these problems much quicker now

Page 9: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 20079

Installed New Gap Adjustment Stand

tuning cancontinuewhile thetechniciansadjust the gap

can use CMMfor feedbackon gapadjustment

the Kuglerbench was usedfor rough tuningwhen required

Page 10: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200710

Beampipe Magnetic Effect Study

Page 11: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200711

Undulator Mounting Tests

MMF Tunnel

kinematic mount:well defined,repeatable

flat on flat:over-constrained, however, thereis compliance in aluminum feetand in the stages, and undulator (?)

Page 12: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200712

Undulator FootUsed For Mounting And Positioning

Page 13: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200713

Issue Under Test

Ideal Error inslot for foot

Correction

Entrance end Exit end

Move axisto correctheight by

adjusting foot

Twists undulator?,distorts foot?

Tooling ball gives axis y position

1 mradroll tolerance,twist is smaller

twist is not the issue

Axis at wrongheight

Page 14: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200714

Tests Of Mounting Method Differences

0.03 mrad,negligible

negligible difference in twist of two undulators tested so farwill check on all undulators

The undulatorappears tosit the sameway on flatfeet as on thekinematicmount.

Page 15: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200715

To-Do List

When we are done with production• fix undulators with severe problems (we need to buy more tapered shims)• study temperature dependence of K• re-measure first five undulators• study further undulator handling requirements

Other Projects• girder alignment plan• build quadrupole coils for gun solenoids

Page 16: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200716

Undulator Quadrupole Fiducialization Plan

Page 17: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200717

Undulator Quadrupole FiducializationSystem Commissioning

Repeatable

flip magnet,center position doesn’t changeno bias from Earth’s field

Page 18: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200718

Undulator Quadrupole Measurements

Scott Andersonwill do the fiducialization

Andrew Fisherwill do the strength

and harmonics measurements

Page 19: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200719

Leftovers From Last FACHall Probe Position Problem

Problem:The vertical trajectories on the Dover bench and Kugler bench did not agree.The horizontal field integrals from the Hall probe had a large y dependence. Coil measurements showed no such dependence.

We stumbled onto a paper Isaacwrote in 1997!

The Sentron probes are sensitiveto planar Hall effects after all!

Page 20: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200720

Solution To The Hall Probe Problem

Isaac’s hypothesis:planar Hall effect

Solution:Measure the positions of the Hall elements.Tune the horizontal trajectory with the By probe on the midplane.Tune the vertical trajectory with the Bx probe on the midplane.Use only the long coil for final field integral measurements.

(30 microns Dover bench,10 microns Kugler bench)

Page 21: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200721

Undulator Sag Changes Hall Probe Y Position Relative To The Midplane

Page 22: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200722

Effect Of Hall Probe Error On Trajectories

y=+200 μm

y=+100 μm

y=0 μm

y=-100 μm

y=-200 μm

2

-2

μm μm

-2

12

-1

6

-2

2

1

-6

2

-14

X Trajectory Y Trajectory

Page 23: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200723

Constant Bx0 Corrects Bx To Long Coil Field Integral

y=+200 μm

y=+100 μm

y=0 μm

y=-100 μm

y=-200 μm

μm

-2

12

-1

6

-2

2

1

-6

2

-14

Y Trajectory Corrected Y Trajectory2

-2

μm

Bx0=+0.52 G

Bx0=+0.29 G

Bx0=0.00 G

Bx0=-0.29 G

Bx0=-0.63 G

Page 24: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200724

Effect Of Undulator Sag And Hall Probe Error On K

Y (μm) K, No Bx0 Correction K, After CorrectionΔK (%), From

Correction

+200 3.491564 3.490271 -0.037

+100 3.488016 3.487728 -0.0083

0 3.486728 3.486728 0.0000

-100 3.487804 3.487244 -0.016

-200 3.491692 3.489325 -0.068

Conclusion:The trajectory curvature caused by the Hall probe error when the undulatorsags by 100 microns will change K by less than 0.016% if no correction isapplied. We do apply a correction, making the effect much smaller.

Page 25: Zachary Wolf LCLS Undulator Tuningwolf@slac.stanford.edu October 30, 2007 1 LCLS Undulator Tuning And Fiducialization Zack Wolf, Yurii Levashov, Achim

Zachary Wolf

LCLS Undulator Tuning [email protected]

October 30, 200725

Conclusion

Production undulator tuning is underway.The lab and equipment are performing well. (But we still need the new air compressor installed.)15 undulators are tuned and fiducialized.Hall probe calibrations are now stable.Reference undulator measurements are within spec.Reference magnet measurements are stable.The magnetic effect of a stainless steel beam pipe was studied.We are checking that the way the undulator is mounted will not change the fiducialization, and twist can be compensated by a pitch adjustment.We have a quadrupole fiducialization plan.The quadrupole fiducialization system was commissioned.After production, we will fix undulators and continue studies.