LCLS Undulator Second Prototype major goals and changes in the design Emil Trakhtenberg Argonne Nati

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LCLS Undulator Second Prototype (major goals and
changes in the design)Emil Trakhtenberg Argonne
National LaboratoryNovember 14, 2003

• Major Challenge
• How to resolve it
• Results of the numerical simulation and first
  tests

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LCLS Second Prototype Undulator(major challenge)

• How to make 35-40 LCLS undulators fully
  identical
• (K value in the order of 10-4)

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LCLS Second Prototype Undulator

• Possible solutions
• Variable gap device
• Electrical correction coils
• Temperature control of each individual undulator
  inside 3 C
• Something completely new.

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LCLS Second Prototype Undulator (temperature
control study 1)
Air-Cooling/Heating (Enclosure)
Advantages
Disadvantages

• Reduces easy access to Undulators
• Not as easy to precisely control air temperature
  compared to water
• Achieving 0.2C temperature stability is
  difficult (1C is more standard)
• Fine control can only be achieved by pushing
  larges volumes of air through the enclosures

• Does not impact Undulator Design
• Stabilizes the entire structure including
  diagnostics
• Commercially available enclosures can be tailored
  to our application

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LCLS Second Prototype Undulator (temperature
control study 2)
Water-Cooling
Advantages
Disadvantages

• Access to Undulators not restricted
• Relatively easy to implement cooling design
• Cooling passages can be integral to the
  strongback structure
• Achieving 0.1C stability with water is
  relatively easy

• Poor conduction path between the strongback and
  magnet holders (may not work as is)
• Can not easily achieve uniformity along undulator
  length (gradients)
• Though reduced, there will still be fluctuations
  in temperatures as a function of room temperature
  fluctuations

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LCLS Second Prototype Undulator (temperature
control study 3)
Active Heating
Advantages
Disadvantages

• 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

• Can use commercially available heaters control
  system
• Fine control is possible if heater layout design
  is properly done

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LCLS Second Prototype Undulator (magnetic shunt
scheme for a numerical simulations)
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LCLS Second Prototype Undulator (peak field
variation with a magnetic shunt)
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LCLS Second Prototype Undulator (magnetic shunt
attractive forces)
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LCLS Second Prototype Undulator Cross
Section(with an actuator)

• Gearbox for 250 kg
• Smartmotor 3120
• Limit switches for the lower and upper
  positions
• Potentiometer with 25 microns resolution.
• Design can be easily modified for manual
  motion

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LCLS Second Prototype Undulator ( with a comb
actuator)
Only one actuator is shown
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LCLS Second Prototype Undulator (half of the
magnet structure with a modification)
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LCLS Second Prototype Undulator ( magnet shunt
acomb)
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LCLS Second Prototype Undulator (comb
deflection)
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LCLS Second Prototype Undulator (alternate
material choice 1)
Casting Processes
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LCLS Second Prototype Undulator (alternate
material choice 2)
Suitable Aluminum Alloy535 (Almag 35)

• Exceptional Dimensional Stability
• Highest combination of
• Strength
• Shock resistance
• Ductility
• Superior Corrosion Resistance
• Machinability
• Machines 4 times faster than other aluminum
  alloys
• Typical uses
• instruments and optical equipment requiring high
  dimensional stability

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LCLS Second Prototype Undulator Aluminum Housing
Initial 3D Model for Analysis
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LCLS Second Prototype Undulator Aluminum Housing
Brans Analysis Improved Model
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LCLS Second Prototype Undulator Titanium Housing
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Acknowledgments

• Isaac Vasserman, Shigemi Sasaki
• Patric Den Hartog, Elizabeth Moog, Mark Erdmann,
  
• John Noonan, Thomas Powers, Branislav
  Brajuskovic, Glen Lawrence, Jeffrey Collins.