major challenge how to resolve it results of the numerical simulation and first tests

LCLS DOE Review, November 14, LCLS DOE Review, November 14, 20032003

Emil Trakhtenberg, ANLEmil Trakhtenberg, ANL LCLS Prototype Undulator DesignLCLS Prototype Undulator Design

[email protected]@aps.anl.gov

Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center

LCLS Undulator Second Prototype (major goals and changes in the design)

Emil Trakhtenberg Argonne National Laboratory

November 14, 2003

LCLS Undulator Second Prototype (major goals and changes in the design)

Emil Trakhtenberg Argonne National Laboratory

November 14, 2003

Major ChallengeMajor Challenge

How to resolve itHow to resolve it

Results of the numerical simulation and first testsResults of the numerical simulation and first tests

Major ChallengeMajor Challenge

How to resolve itHow to resolve it

Results of the numerical simulation and first testsResults of the numerical simulation and first tests





LCLS Second Prototype UndulatorLCLS Second Prototype Undulator(major challenge)(major challenge)

How to make 35-40 LCLS How to make 35-40 LCLS undulators fully identicalundulators fully identical

(K value in the order of 10(K value in the order of 10-4)-4)

How to make 35-40 LCLS How to make 35-40 LCLS undulators fully identicalundulators fully identical

(K value in the order of 10(K value in the order of 10-4)-4)





LCLS Second Prototype UndulatorLCLS Second Prototype Undulator

Possible solutions:Possible solutions:

1.1. Variable gap device;Variable gap device;

2.2. Electrical correction coils;Electrical correction coils;

3.3. Temperature control of each individual undulator Temperature control of each individual undulator inside ±3° C;inside ±3° C;

4.4. Something completely new.Something completely new.

Possible solutions:Possible solutions:

1.1. Variable gap device;Variable gap device;

2.2. Electrical correction coils;Electrical correction coils;

3.3. Temperature control of each individual undulator Temperature control of each individual undulator inside ±3° C;inside ±3° C;

4.4. Something completely new.Something completely new.





LCLS Second Prototype Undulator (temperature control study 1)


Air-Cooling/Heating (Enclosure)Advantages Disadvantages

•Does not impact Undulator Design

•Stabilizes the entire structure including diagnostics

•Commercially available enclosures can be tailored to our application

•Reduces easy access to Undulators

•Not as easy to precisely control air temperature compared to water

•Achieving 0.2°C temperature stability is difficult (1°C is more standard)

•Fine control can only be achieved by pushing larges volumes of air through the enclosures







Water-Cooling

Access to Undulators not Access to Undulators not restrictedrestricted

Relatively easy to implement Relatively easy to implement cooling designcooling design

Cooling passages can be integral Cooling passages can be integral to the strongback structureto the strongback structure

Achieving 0.1°C stability with Achieving 0.1°C stability with water is relatively easywater is relatively easy

Poor conduction path between the Poor conduction path between the strongback and magnet holders strongback and magnet holders (may not work as is)(may not work as is)

Can not easily achieve uniformity Can not easily achieve uniformity along undulator length (gradients)along undulator length (gradients)

Though reduced, there will still be Though reduced, there will still be fluctuations in temperatures as a fluctuations in temperatures as a function of room temperature function of room temperature fluctuationsfluctuations

Advantages Disadvantages







Active HeatingAdvantages Disadvantages

•Can use commercially available heaters & control system

•Fine control is possible if heater layout design is properly done

•Very complicated heater layout required to achieve stability and uniformity

•Complicates the Undulator design and fabrication

•Sophisticated variable power and PID control systems required for each Undulator

•Gradients are inherent in the design





LCLS Second Prototype Undulator (magnetic shunt scheme for a numerical simulations)

LCLS Second Prototype Undulator (magnetic shunt scheme for a numerical simulations)





LCLS Second Prototype Undulator (peak field variation with a magnetic shunt)

LCLS Second Prototype Undulator (peak field variation with a magnetic shunt)

Peak Field Variations

1.462

1.464

1.466

1.468

1.470

1.472

1.474

1.476

6 8 10 12 14 16

Space [mm]

Pea

k F

ield

[T

]

Series1

Series2





LCLS Second Prototype Undulator (magnetic shunt attractive forces)

LCLS Second Prototype Undulator (magnetic shunt attractive forces)

Fz [kgf], 8 poles

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

6 8 10 12 14 16

Distance [mm]

Fo

rce

[kg

f]





LCLS Second Prototype Undulator Cross Section(with an actuator)

LCLS Second Prototype Undulator Cross Section(with an actuator)

Gearbox for 250 kg;Gearbox for 250 kg; ““Smartmotor “ 3120;Smartmotor “ 3120; Limit switches for the Limit switches for the

lower and upper lower and upper positions;positions;

Potentiometer with 25 Potentiometer with 25 microns resolution.microns resolution.

Design can be easily Design can be easily modified for manual modified for manual motionmotion

Gearbox for 250 kg;Gearbox for 250 kg; ““Smartmotor “ 3120;Smartmotor “ 3120; Limit switches for the Limit switches for the

lower and upper lower and upper positions;positions;

Potentiometer with 25 Potentiometer with 25 microns resolution.microns resolution.

Design can be easily Design can be easily modified for manual modified for manual motionmotion





LCLS Second Prototype Undulator ( with a “comb” actuator)

LCLS Second Prototype Undulator ( with a “comb” actuator)

Only one actuator is shown





LCLS Second Prototype Undulator (half of the magnet structure with a modification)

LCLS Second Prototype Undulator (half of the magnet structure with a modification)





LCLS Second Prototype Undulator ( magnet shunt – a”comb”)

LCLS Second Prototype Undulator ( magnet shunt – a”comb”)





LCLS Second Prototype Undulator (”comb” deflection)

LCLS Second Prototype Undulator (”comb” deflection)





LCLS Second Prototype Undulator (alternate material choice 1)


Casting Processes

Casting ProcessCasting Process Applicable to Applicable to StrongbackStrongback

Die CastingDie Casting NoNo

Investment CastingInvestment Casting NoNo

Permanent Mold CastingPermanent Mold Casting NoNo

Green Sand CastingGreen Sand Casting YesYes

Dry Sand CastingDry Sand Casting YesYes

No-Bake Sand CastingNo-Bake Sand Casting YesYes

V-Process CastingV-Process Casting NoNo







Suitable Aluminum Alloy535 (Almag 35)

•Exceptional Dimensional StabilityExceptional Dimensional Stability•Highest combination ofHighest combination of

–Strength–Shock resistance–Ductility

•Superior Corrosion ResistanceSuperior Corrosion Resistance•MachinabilityMachinability

–Machines 4 times faster than other aluminum alloys•Typical usesTypical uses

– instruments and optical equipment requiring high dimensional stability





LCLS Second Prototype Undulator Aluminum HousingLCLS Second Prototype Undulator Aluminum Housing

Initial 3D Model for AnalysisInitial 3D Model for Analysis





LCLS Second Prototype Undulator Aluminum HousingLCLS Second Prototype Undulator Aluminum Housing

Bran’s Analysis Improved ModelBran’s Analysis Improved Model





LCLS Second Prototype Undulator Titanium HousingLCLS Second Prototype Undulator Titanium Housing





AcknowledgmentsAcknowledgments

Isaac Vasserman, Shigemi Sasaki Isaac Vasserman, Shigemi Sasaki

Patric Den Hartog, Elizabeth Moog, Mark Patric Den Hartog, Elizabeth Moog, Mark Erdmann, Erdmann,

John Noonan, Thomas Powers, Branislav John Noonan, Thomas Powers, Branislav Brajuskovic, Glen Lawrence, Jeffrey Collins.Brajuskovic, Glen Lawrence, Jeffrey Collins.

Isaac Vasserman, Shigemi Sasaki Isaac Vasserman, Shigemi Sasaki

Patric Den Hartog, Elizabeth Moog, Mark Patric Den Hartog, Elizabeth Moog, Mark Erdmann, Erdmann,

John Noonan, Thomas Powers, Branislav John Noonan, Thomas Powers, Branislav Brajuskovic, Glen Lawrence, Jeffrey Collins.Brajuskovic, Glen Lawrence, Jeffrey Collins.

major challenge how to resolve it results of the numerical simulation and first tests

Documents

elizabeth moog

isaac vasserman

glen lawrence

branislav brajuskovic

thomas powers

john noonan

mark erdmann

jeffrey collins