Undulator Systems Efim Gluskin, ANL April 23, 2002

1. Undulator SystemsEfim Gluskin, ANLApril 23, 2002 • Overview • Specifications • Prototypes • Magnetic system • Mechanical system • Diagnostics • Cost & Schedule Efim Gluskin, ANL

2. Undulator Systems WBS 1.2.3 Undulator Systems WBS 1.2.3 Efim Gluskin, ANL

3. List of the Undulator Line Systems • Undulator magnetic structure • periodic magnetic structure • end’s termination • strongback • Mechanical support - movers • Quadrupole Lens • Coils - correctors • E-beam position monitors • X-ray diagnostics • Undulator vacuum chamber and diagnostics station • Controls and data acquisition • Support laboratory - magnet measurement facility Efim Gluskin, ANL

4. Cell structure of the LCLS undulator line 421 187 3420 UNDULATOR 11055 mm Horizontal Steering Coil Vertical Steering Coil Beam Position Monitor X-Ray Diagnostics Quadrupoles Efim Gluskin, ANL

5. Saturation length (m) vs. undulator period and average ß-function Efim Gluskin, ANL

6. 16 perfect imperfect Z 0 100 Fast code RON-tool for developing of specifications The saturation length increase ∆LS due to imperfections. Efim Gluskin, ANL

7. L E U T L : T r a j e c t o r y f r o m 5 Distance along FEL (m) Undulator’s Performance and Computer Modeling of SASE • N e w c o m p u t e r c o d e h a s b e e n d e v e l o p e d a t t h e A P S t o a i d i n t h e d e s i g n o p t i m i z a t i o n o f h i g h - g a i n , s h o r t - w a v e l e n g t h f r e e - e l e c t r o n l a s • Undulator’s performance is close to theoretically achievable. • Computer codes calculate SASE signal growth and take into account all imperfections of the undulator line. • T h e c o d e c a l c u l a t e s t h e s i g n a l g r o w t h o f t h e b e a m c u r r e n t d e n s i t y v s . d i s t a n c e a l o n g t h e u n d u l a t o r . • T h e c o d e t a k e s i n t o a c c o u n t n o n - i d e a l m a g n e t i c s y s t e m s , s u c h a s s e g m e n t e d u n d u l a t o r s w i t h d i s t r i b u t e d f o c u s i n g , r e a l m e a s u r e d m a g n e t i c f i e l d f i l e s , a n d m i s a l i g n e d u n d u l a t o r s . LEUTL: SASE power vs. distance (5 undulators) LEUTL: Trajectory from 5 measured undulators L E U T L : S A S E p o w e r v s . d i s t a n c e ( 5 u n d u l a t o r s ) m e a s u r e d u n d u l a t o r s Power (arbitrary units) Horizontal trajectoy (µm) Ideal undulators Measured undulators I d e a l u n d u l a t o r s M e a s u r e d u n d u l a t o r s Distance along FEL (m) Distance along FEL (m) Distance along FEL (m) NIM, A445, pp.19-23 (2000) Efim Gluskin, ANL

8. A0is a measured value for the reference ID. A represents all other ID’s These tolerances correspond to approximately 3% growth of the gain length. Tolerances for the LCLS undulator section (undulator + quadrupole) Phase slippage over the length of one section Efim Gluskin, ANL

9. Definition of the Parameter A Intensity of Zero-angle spontaneous radiation at frequency ck is , where Efim Gluskin, ANL

10. B0 Uniformity Quantative approach: for 23 IDs leads to Efim Gluskin, ANL

11. Prototype Module Efim Gluskin, ANL

12. Total Magnetic Moment (T) Magnets in order of increasing magnetic moment Magnet Block Strength Efim Gluskin, ANL

13. After pairing the magnets by matching strong to weak, to even out the distribution. Magnet Strength after Pairing Efim Gluskin, ANL

14. Magnetic Measurement of the Prototype Horizontal Trajectory Microns Efim Gluskin, ANL

15. Phase Advance N- number of poles For one undulator section z1 z z2 z3 Phasing of the Undulator Sections End’s section Efim Gluskin, ANL

16. when It translates in the gap g increase: Where is the ratio of the coherent and spontaneous radiation power. Tapering Efim Gluskin, ANL

17. Test of Undulator Movers Efim Gluskin, ANL

18. Quadropole Lens Prototype Field gradient G = 75T/m Magnetic length lm = 5.6cm Focal length F = 11.3m Efim Gluskin, ANL

19. Vacuum System • Two different sections: • Pipe in the undulator • Diagnostics vacuum chamber • General requirement : ≈10-7torr • Influence of the pipe’s wall roughness • Discontinuity of the vacuum surface • Transitions and liners Efim Gluskin, ANL

20. Conceptual Design for Combined Button / Cavity BPM Button BPM 1µ or better single shot resolution 1-2µ stability over periods of hours 50µ absolute accuracy Cavity BPM 5µ absolute accuracy submicron stability Efim Gluskin, ANL

21. CCD CCD l = 2.9 Å PIN diode Undulator cell l = 1.5 Å Diamond crystal X-Ray Diagnostics Setup X-ray diagnostics will be located in the last break of each undulator cell, it includes: - x-ray diamond crystal monochromator - PIN diode detectors and attenuation filters for absolute flux measurements - CCD detectors for spatial measurements Efim Gluskin, ANL

22. X-Ray Diagnostics - Summary • X-ray diagnostics will provide direct measurements of absolute spectral flux and spatial properties of spontaneous and SASE radiation along the undulator line It will meet the following requirements: • one-shot sensitivity for all types of spectral, flux, and spatial measurements • many orders of magnitude dynamic range • accuracy of the absolute flux measurement better than 10% • few microradian sensitivity for trajectory straightness Efim Gluskin, ANL

23. 1.2.3 Undulator Cost Estimate (FY02 Dollars, Thousands) Efim Gluskin, ANL

24. 1.2.3.1 Undulator PED Cost Estimate (FY02 Dollars, Thousands) Efim Gluskin, ANL

25. Undulator System Schedule Efim Gluskin, ANL

26. PED Milestones Milestone Date Design of 2nd undulator prototype 1/1/03 Diagnostics specifications completed 4/1/03 Preliminary design of diagnostics completed 7/1/03 Preliminary design of vacuum chamber 8/1/03 Assembly of 2nd prototype undulator complete 9/2/03 Final design of undulator complete 12/2/03 Prototype vacuum chamber assembled 2/1/04 Bid package for undulator complete 4/1/04 Final design of vacuum chamber complete 8/1/04 Diagnostics, vacuum chamber, electromagnet bid package complete 10/1/04 Efim Gluskin, ANL