LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 1 LCLS Undulator Second Prototype (major goals and changes in the design) Emil Trakhtenberg Argonne National Laboratory November 14, 2003 Major Challenge How to resolve it Results of the numerical simulation and first tests Major Challenge How to resolve it Results of the numerical simulation and first tests

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 2 LCLS Second Prototype Undulator (major challenge) How to make LCLS undulators fully identical (K value in the order of 10 -4) How to make LCLS undulators fully identical (K value in the order of 10 -4)

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 3 LCLS Second Prototype Undulator Possible solutions: 1.Variable gap device; 2.Electrical correction coils; 3.Temperature control of each individual undulator inside ±3° C; 4.Something completely new. Possible solutions: 1.Variable gap device; 2.Electrical correction coils; 3.Temperature control of each individual undulator inside ±3° C; 4.Something completely new.

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 4 LCLS Second Prototype Undulator (temperature control study 1) Air-Cooling/Heating (Enclosure) AdvantagesDisadvantages 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

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 5 LCLS Second Prototype Undulator (temperature control study 2) Water-Cooling Access to Undulators not restricted Relatively easy to implement cooling design Cooling passages can be integral to the strongback structure Achieving 0.1°C 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 Advantages Disadvantages

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 6 LCLS Second Prototype Undulator (temperature control study 3) Active Heating AdvantagesDisadvantages 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 Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 7 LCLS Second Prototype Undulator (magnetic shunt scheme for a numerical simulations)

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 8 LCLS Second Prototype Undulator (peak field variation with a magnetic shunt)

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 9 LCLS Second Prototype Undulator (magnetic shunt attractive forces)

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 10 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 Design can be easily modified for manual motion

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 11 LCLS Second Prototype Undulator ( with a “comb” actuator) Only one actuator is shown

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 12 LCLS Second Prototype Undulator (half of the magnet structure with a modification)

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 13 LCLS Second Prototype Undulator ( magnet shunt – a”comb”)

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 14 LCLS Second Prototype Undulator (”comb” deflection)

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 15 LCLS Second Prototype Undulator (alternate material choice 1) Casting Processes Casting Process Applicable to Strongback Die Casting No Investment Casting No Permanent Mold Casting No Green Sand Casting Yes Dry Sand Casting Yes No-Bake Sand Casting Yes V-Process Casting No

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 16 LCLS Second Prototype Undulator (alternate material choice 2) Suitable Aluminum Alloy 535 (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 Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 17 LCLS Second Prototype Undulator Aluminum Housing Initial 3D Model for Analysis

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 18 LCLS Second Prototype Undulator Aluminum Housing Bran’s Analysis Improved Model

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 19 LCLS Second Prototype Undulator Titanium Housing

LCLS Prototype Undulator Design LCLS Prototype Undulator Design Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS DOE Review, November 14, 2003 Emil Trakhtenberg, ANL 20 Acknowledgments Isaac Vasserman, Shigemi Sasaki Patric Den Hartog, Elizabeth Moog, Mark Erdmann, Patric Den Hartog, Elizabeth Moog, Mark Erdmann, John Noonan, Thomas Powers, Branislav Brajuskovic, Glen Lawrence, Jeffrey Collins. Isaac Vasserman, Shigemi Sasaki Patric Den Hartog, Elizabeth Moog, Mark Erdmann, Patric Den Hartog, Elizabeth Moog, Mark Erdmann, John Noonan, Thomas Powers, Branislav Brajuskovic, Glen Lawrence, Jeffrey Collins.