Transcript ETRev1b.ppt
Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center 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 LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 1 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator (major challenge) How to make 35-40 LCLS undulators fully identical (K value in the order of 10-4) LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 2 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center 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. LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 3 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center 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 LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 4 •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 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center 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 0.1°C stability with water is relatively easy LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 5 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 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator (temperature control study 3) Active Heating Advantages •Can use commercially available heaters & control system •Fine control is possible if heater layout design is properly done LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 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 6 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator (magnetic shunt scheme for a numerical simulations) LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 7 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator (peak field variation with a magnetic shunt) Peak Field Variations 1.476 Peak Field [T] 1.474 1.472 1.470 1.468 Series1 1.466 Series2 1.464 1.462 6 8 10 12 14 16 Space [mm] LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 8 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator (magnetic shunt attractive forces) Fz [kgf], 8 poles 0 -5 Force [kgf] -10 -15 -20 -25 -30 -35 -40 -45 6 8 10 12 14 16 Distance [mm] LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 9 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center 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 LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 10 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator ( with a “comb” actuator) Only one actuator is shown LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 11 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator (half of the magnet structure with a modification) LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 12 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator ( magnet shunt – a”comb”) LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 13 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator (”comb” deflection) LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 14 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center 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 DOE Review, November 14, 2003 LCLS Prototype Undulator Design 15 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator (alternate material choice 2) Suitable Aluminum Alloy 535 (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 LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 16 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator Aluminum Housing Initial 3D Model for Analysis LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 17 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator Aluminum Housing Bran’s Analysis Improved Model LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 18 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center LCLS Second Prototype Undulator Titanium Housing LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 19 Emil Trakhtenberg, ANL [email protected] Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Acknowledgments Isaac Vasserman, Shigemi Sasaki Patric Den Hartog, Elizabeth Moog, Mark Erdmann, John Noonan, Thomas Powers, Branislav Brajuskovic, Glen Lawrence, Jeffrey Collins. LCLS DOE Review, November 14, 2003 LCLS Prototype Undulator Design 20 Emil Trakhtenberg, ANL [email protected]