1. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 1 Physics Requirements Heinz-Dieter Nuhn, SLAC / LCLS October 20, 2005 System Component Description Tolerance Budget based on Genesis Simulations Requirements and Procedures System Component Description Tolerance Budget based on Genesis Simulations Requirements and Procedures

2. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 2 Linac Coherent Light Source Near Hall Far Hall Undulator

3. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 3

4. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 4 Undulator Type planar hybrid Magnet Material NdFeB Wiggle Planehorizontal Gap6.8mm Period Length30.0±0.05mm Effective On-Axis Field1.249T Range of Effective Undulator Parameter K3.500 - 3.493 (3.480) Tolerance for K± 0.015% Accumulated Segment Phase Error Tolerance ± 10degrees (at any point along segment) Segment Length3.40m Number of Segments33 Undulator Magnetic Length112.2m Standard Break Lengths 47.0 - 47.0 - 89.8 cm Nominal Total Device Length131.52m Quadrupole Magnet Technology EMQ Nominal Quadrupole Magnet Length 7cm Integrated Quadrupole Gradient 3.0T Undulator Type planar hybrid Magnet Material NdFeB Wiggle Planehorizontal Gap6.8mm Period Length30.0±0.05mm Effective On-Axis Field1.249T Range of Effective Undulator Parameter K3.500 - 3.493 (3.480) Tolerance for K± 0.015% Accumulated Segment Phase Error Tolerance ± 10degrees (at any point along segment) Segment Length3.40m Number of Segments33 Undulator Magnetic Length112.2m Standard Break Lengths 47.0 - 47.0 - 89.8 cm Nominal Total Device Length131.52m Quadrupole Magnet Technology EMQ Nominal Quadrupole Magnet Length 7cm Integrated Quadrupole Gradient 3.0T Summary of Nominal Undulator Parameters

5. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 5 Undulator Segment Prototype

6. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 6 Short Break Section Components Courtesy of Dean Walters Quadrupole Undulator Segment Cherenkov Detector Undulator Segment RF Cavity BPM Beam Finder Wire

7. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 7 Long Break Section Components Courtesy of Dean Walters Quadrupole Undulator Segment Cherenkov Detector Undulator Segment Diagnostics Tank Beam Finder Wire RF Cavity BPM

8. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 8 Requirement Documents Doc TypeNumberTitle GRD1.1-001Global Requirement Document http://ssrl.slac.stanford.edu/lcls/prd/1.1-001-r1.pdf http://ssrl.slac.stanford.edu/lcls/prd/1.1-001-r1.pdf PRD1.1-002LCLS Start-Up Test Plan http://ssrl.slac.stanford.edu/lcls/prd/1.1-002-r0.pdf http://ssrl.slac.stanford.edu/lcls/prd/1.1-002-r0.pdf PRD1.1-003Conventional Alignment System Requirements http://ssrl.slac.stanford.edu/lcls/prd/1.1-003-r1.pdf http://ssrl.slac.stanford.edu/lcls/prd/1.1-003-r1.pdf PRD1.4-001General Undulator System Requirements http://ssrl.slac.stanford.edu/lcls/prd/1.4-001-r3.pdf http://ssrl.slac.stanford.edu/lcls/prd/1.4-001-r3.pdf PRD1.4-002Magnetic Measurement Facility Requirements http://ssrl.slac.stanford.edu/lcls/prd/1.4-002-r0.pdf http://ssrl.slac.stanford.edu/lcls/prd/1.4-002-r0.pdf PRD1.4-003Undulator Beam Based Alignment System Requirements http://ssrl.slac.stanford.edu/lcls/prd/1.4-003-r2.pdf http://ssrl.slac.stanford.edu/lcls/prd/1.4-003-r2.pdf PRD1.4-004Undulator Beam Finder Wire http://ssrl.slac.stanford.edu/lcls/prd/1.4-004-r0.pdf http://ssrl.slac.stanford.edu/lcls/prd/1.4-004-r0.pdf ESD1.4-104Wire Position Monitor System Specifications ESD1.4-105Hydrostatic Leveling System Specifications http://ssrl.slac.stanford.edu/lcls/prd/1.4-105-r0.pdf http://ssrl.slac.stanford.edu/lcls/prd/1.4-105-r0.pdf

9. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 9 LCLS Undulator Tolerance Budget Analysis Based On Time Dependent SASE Simulations in 2 Phases Simulation Code: Genesis 1.3 Simulate Individual Error Sources Combine Results into Error Budget Based On Time Dependent SASE Simulations in 2 Phases Simulation Code: Genesis 1.3 Simulate Individual Error Sources Combine Results into Error Budget

10. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 10 Parameters for Tolerance Study The following 8 errors are considered: Beta-Function Mismatch, Launch Position Error, Module Detuning, Module Offset in x, Module Offset in y, Quadrupole Gradient Error, Transverse Quadrupole Offset, Break Length Error. The ‘observed’ parameter is the average of the FEL power at 90 m (around saturation) and 130 m (undulator exit) The following 8 errors are considered: Beta-Function Mismatch, Launch Position Error, Module Detuning, Module Offset in x, Module Offset in y, Quadrupole Gradient Error, Transverse Quadrupole Offset, Break Length Error. The ‘observed’ parameter is the average of the FEL power at 90 m (around saturation) and 130 m (undulator exit)

11. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 11 Step I - Individual Study Time-dependent runs with increasing error source (uniform distribution) and different error seeds. Gauss fit to obtain rms-dependence. Detailed Analysis Description

12. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 12 Step I – Error 1b: Optics Mismatch Simulation and fit results of Optics Mismatch analysis. The larger amplitude data occur at the 114-m- point, the smaller amplitude data at the 80-m-point. Optics Mismatch (Gauss Fit) LocationFit rmsUnit 080 m0.58 114 m0.71 Average0.64 Transformation from negative exponential to Gaussian:  < 1.41 Z. Huang Simulations

13. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 13 Comparison of  vs.  /  0 1-  value Simplifies at waist location: + - or, resolved for 

14. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 14 Step I – Error 2: Transverse Beam Offset Transverse Beam Offset (Gauss Fit) / LocationFit rmsUnit 090 m25.1µm 130 m21.1µm Average23.1µm Simulation and fit results of Transverse Beam Offset (Launch Error) analysis. The larger amplitude data occur at the 130-m-point, the smaller amplitude data at the 90-m- point.

15. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 15 Step I – Error 3: Module Detuning Module Detuning (Gauss Fit) LocationFit rmsUnit 090 m0.042% 130 m0.060% Average0.051% Simulation and fit results of Module Detuning analysis. The larger amplitude data occur at the 130-m- point, the smaller amplitude data at the 90-m-point.

16. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 16 Step I – Error 4: Horizontal Module Offset Horizontal Model Offset (Gauss Fit) LocationFit rmsUnit 090 m0782µm 130 m1121µm Average0952µm Simulation and fit results of Horizontal Module Offset analysis. The larger amplitude data occur at the 130-m- point, the smaller amplitude data at the 90-m-point.

17. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 17 Step I – Error 5: Vertical Module Offset Vertical Model Offset (Gauss Fit) LocationFit rmsUnit 090 m268µm 130 m268µm Average268µm Simulation and fit results of Vertical Module Offset analysis. The larger amplitude data occur at the 130-m- point, the smaller amplitude data at the 90-m-point.

18. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 18 Step I – Error 6: Quad Field Variation Quad Field Variation (Gauss Fit) LocationFit rmsUnit 090 m8.7% 130 m8.8% Average8.7% Simulation and fit results of Quad Field Variation analysis. The larger amplitude data occur at the 130-m- point, the smaller amplitude data at the 90-m-point.

19. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 19 Step I – Error 7: Transverse Quad Offset Error Transverse Quad Offset Error (Gauss Fit) LocationFit rmsUnit 090 m4.1µm 130 m4.7µm Average4.4µm Simulation and fit results of Transverse Quad Offset Error analysis. The larger amplitude data occur at the 130-m-point, the smaller amplitude data at the 90-m-point.

20. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 20 Step I – Error 8: Break Length Error Break Length Error (Gauss Fit) LocationFit rmsUnit 090 m13.9mm 130 m20.3mm Average17.1mm Simulation and fit results of Break Length Error analysis. The larger amplitude data occur at the 130-m- point, the smaller amplitude data at the 90-m-point.

21. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 21 Step II - Tolerance Budget Assuming that each error is independent on each other (validity of this assumption is limited) Each should yield the same degradation Tolerance is defined for a given power degradation 1 - P/P 0 f 20 %0.236 25 %0.268 n = 8 tolerance fitted rms fi=xi/ifi=xi/i fi=xi/ifi=xi/i unit weights

22. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 22 Step III - Correlated Error Sources For the simplest approach, the tolerance budget assumes uncorrelated errors of 8 different sources. Some tolerances (e.g. the break length error) are very relaxed and can be reduced to relax other tolerances, i.e. use individual tolerances. Next step is to combine all error sources in the simulation. Include BBA and other correction scheme in the runs For the simplest approach, the tolerance budget assumes uncorrelated errors of 8 different sources. Some tolerances (e.g. the break length error) are very relaxed and can be reduced to relax other tolerances, i.e. use individual tolerances. Next step is to combine all error sources in the simulation. Include BBA and other correction scheme in the runs

23. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 23 Step II - Tolerance Budget (cont’) Error Source  i  i  f fifi  i  f i Units f=0.268 (25% red.)(24.2% red.) Hor/Ver Optics Mismatch (  -1) 0.5 0.640.190.4530.32 Hor/Ver Transverse Beam Offset235.70.1773.7µm Module Detuning  K/K 0.0510.0160.4020.024% Module Offset in x9523010.125140µm Module Offset in y268720.29880µm Quadrupole Gradient Error8.72.30.0280.25% Transverse Quadrupole Offset4.41.30.2151.0µm Break Length Error17.15.40.0481.0mm Can be mitigated through steering.  < 1.1

24. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 24 Model Detuning Sub-Budget Parameter p i Typical Value rms dev.  p i Note K MMF 3.50.0003±0.015 % uniform KK -0.0019 °C -1 0.0001 °C -1 Thermal Coefficient TT 0 °C0.32 °C±0.56 °C uniform without compensation KK 0.0023 mm -1 0.00004 mm -1 Canting Coefficient xx 1.5 mm0.05 mmHorizontal Positioning

25. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 25 Undulator Pole Canting Canting comes from wedged spacers 4.5 mrad cant angle Gap can be adjusted by lateral displacement of wedges 1 mm shift means 4.5 microns in gap, or 8.2 Gauss B eff adjusted to desired value

26. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 26 Using Undulator Roll-Away and K Adjustment Function Neutral; K=3.5000;  x=+0.0 mm SpontTp; K=3.4929;  x=+3.0 mmRollAway; K=0.0000;  x=+100 mm PowerTp; K=3.4804;  x=+8.5 mm Standard Undulator Segment Axis (SUSA) as defined during tuning process. SUSA defines Girder Axis (GA) in neutral Segment position. SUSA moves with Segment, GA does not. Both axes refer to undulator fiducials. GA is the basic reference line for the relative alignment of Beamline components. Standard Undulator Segment Axis (SUSA) as defined during tuning process. SUSA defines Girder Axis (GA) in neutral Segment position. SUSA moves with Segment, GA does not. Both axes refer to undulator fiducials. GA is the basic reference line for the relative alignment of Beamline components. SUSA GA SUSA GA

27. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 27 Segment K Adjustments for Overall Tapering The following list contains the nominal K values for the 33 undulator segments for the 6.8 mm gap height: This amount of tapering requires only a negligible adjustment for break lengths. After achieving goal performance, tapering beyond saturation point is desirable. (up to 0.6% total) This amount of tapering requires only a negligible adjustment for break lengths. After achieving goal performance, tapering beyond saturation point is desirable. (up to 0.6% total) Undulator SegmentK eff 13.5000 23.4998 33.4996 43.4993 53.4991 63.4989 73.4987 83.4984 93.4982 103.4980 113.4978 123.4976 133.4973 143.4971 153.4969 163.4967 173.4964 183.4962 193.4960 203.4958 213.4955 223.4953 233.4951 243.4949 253.4947 263.4944 273.4942 283.4940 293.4938 303.4935 313.4933 323.4931 333.4929 To compensate energy loss from spontaneous radiation

28. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 28 Measurement of SASE Gain Using Rollout Undulator Segments can be removed by remote control from the end of the undulator. They will not effect radiation produced by earlier segments.

29. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 29 Root Requirements for FEL Gain Effective K Value Tolerance The effective K value for each undulator along the electron path shall not deviate by more that ±0.024 % from its design value. Undulator Tuning Temperature Control Undulator Segment Alignment Pole Canting with Horizontal Position Control Phase Tolerance The average longitudinal electron bunch position shall not deviate by more that ±10 degrees of x-ray phase (±4 pm) from its design value over the distance of one gain length. Trajectory Control (Tight Control and Stability of Quadrupole Centers) Overlap Tolerance The rms deviation between the transverse center of the electron beam and the center of the radiation field shall be less than 10% of the rms of the electron beam distribution. Control and Stabilization of Launch Coordinates Trajectory Control Effective K Value Tolerance The effective K value for each undulator along the electron path shall not deviate by more that ±0.024 % from its design value. Undulator Tuning Temperature Control Undulator Segment Alignment Pole Canting with Horizontal Position Control Phase Tolerance The average longitudinal electron bunch position shall not deviate by more that ±10 degrees of x-ray phase (±4 pm) from its design value over the distance of one gain length. Trajectory Control (Tight Control and Stability of Quadrupole Centers) Overlap Tolerance The rms deviation between the transverse center of the electron beam and the center of the radiation field shall be less than 10% of the rms of the electron beam distribution. Control and Stabilization of Launch Coordinates Trajectory Control

30. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 30 Implication from Phase Tolerance Tight Phase Tolerance Requires Extremely straight trajectory (~3 µm rms over 10 m) Precise positioning of quadrupoles (±2 µm wrt. straight line) Use of Beam Based Alignment (BBA) methods Basic Conventional Alignment and Motion Strategy Alignment of components as needed to start BBA Monitoring of component motion during and between BBA procedures. The latter is to mitigate effects of ground motion and to lengthen time needed between BBA procedures. Tight Phase Tolerance Requires Extremely straight trajectory (~3 µm rms over 10 m) Precise positioning of quadrupoles (±2 µm wrt. straight line) Use of Beam Based Alignment (BBA) methods Basic Conventional Alignment and Motion Strategy Alignment of components as needed to start BBA Monitoring of component motion during and between BBA procedures. The latter is to mitigate effects of ground motion and to lengthen time needed between BBA procedures.

31. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 31 Main Alignment Monitoring Elements Hydrostatic Leveling System Device (HLS) Monitored Degrees of Freedom: y, pitch, and roll Wire Position Monitoring Device (WPM) Monitored Degrees of Freedom: x, yaw, and roll Temperature Sensors BPMs (Transverse Locations Tracked by HLS and WPM) Hydrostatic Leveling System Device (HLS) Monitored Degrees of Freedom: y, pitch, and roll Wire Position Monitoring Device (WPM) Monitored Degrees of Freedom: x, yaw, and roll Temperature Sensors BPMs (Transverse Locations Tracked by HLS and WPM)

32. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 32 Main Alignment Control Elements Relative alignment between undulator segments and break section components will be achieved and maintained through common-girder mounting Overall alignment are (remotely) controlled through Girder movement based on cam-shaft technology During initial alignment For quadrupole position control, i.e. beam steering during BBA For compensation of ground motion effects etc. Quadrupoles are used as beam steering elements Main steering function comes from off-center dipole fields. Change is done through cam-based girder motion, which will align all girder components to the beam. Dipole trim-windings are used for fine adjustments Relative alignment between undulator segments and break section components will be achieved and maintained through common-girder mounting Overall alignment are (remotely) controlled through Girder movement based on cam-shaft technology During initial alignment For quadrupole position control, i.e. beam steering during BBA For compensation of ground motion effects etc. Quadrupoles are used as beam steering elements Main steering function comes from off-center dipole fields. Change is done through cam-based girder motion, which will align all girder components to the beam. Dipole trim-windings are used for fine adjustments

33. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 33 Girder Components Summary Main girder components include Beam Finder Wire Undulator strongback arrangement mounted on horizontal slides Vacuum chamber support BPM Quadrupole WPM sensors HLS sensors (diagnostics components) The undulator strongback arrangement (Segment) is mountable on and removable from the girder with the vacuum chamber in place and without compromising the alignment of the vacuum chamber Segments will be taken off the girder for magnetic measurements Segments need to be mechanically interchangeable The complete Girder assembly will be aligned on the Coordinate Measurement Machine (CMM). Main girder components include Beam Finder Wire Undulator strongback arrangement mounted on horizontal slides Vacuum chamber support BPM Quadrupole WPM sensors HLS sensors (diagnostics components) The undulator strongback arrangement (Segment) is mountable on and removable from the girder with the vacuum chamber in place and without compromising the alignment of the vacuum chamber Segments will be taken off the girder for magnetic measurements Segments need to be mechanically interchangeable The complete Girder assembly will be aligned on the Coordinate Measurement Machine (CMM).

34. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 34 Undulator Motion Summary Remotely Controlled Motion: Undulator: x Provides control of undulator field on beam axis. Horizontal slide stages move undulator strongback independent of Girder and vacuum chamber. Girder: x, y, pitch, yaw, roll Enables alignment of all beamline components to beam axis. transverse motion of meeting girder ends can be coupled roll motion capability is to be used to keep roll constant Additional Manual Adjustments: Rough CAM position adjustability relative to fixed support. Quadrupole, BFW, Vacuum Chamber, and BPM position adjustability to Girder. Remotely Controlled Motion: Undulator: x Provides control of undulator field on beam axis. Horizontal slide stages move undulator strongback independent of Girder and vacuum chamber. Girder: x, y, pitch, yaw, roll Enables alignment of all beamline components to beam axis. transverse motion of meeting girder ends can be coupled roll motion capability is to be used to keep roll constant Additional Manual Adjustments: Rough CAM position adjustability relative to fixed support. Quadrupole, BFW, Vacuum Chamber, and BPM position adjustability to Girder.

35. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 35 Segment Alignment using Beam Finder Wire Downstream quad and upstream monitor fiducialized to undulator ends BBA facilitates alignment of downstream cradle end and straightens electron beam Use Beam Finder Wire reading to determine and correct “loose” end offset Monitoring System WPM and HLS provide real-time girder position information Info can be used as feed-back for mover system to maintain initial alignment Before any BBA performed After BBA: Quad, BPM and one end of undulator aligned After centering of Upstream Monitor: Both ends of undulator aligned Quad RF BPM Undulator Strongback Girder Beam Finder Wire Beam

36. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 36 Undulator – to – BFW Alignment Tolerance Budget Individual contributions are added in quadrature

37. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 37 Undulator – to – Quad Alignment Tolerance Budget Individual contributions are added in quadrature

38. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 38 Main Alignment Procedures Overview Undulator Segment Tuning and Fiducialization (Establishes SUSA) Quadrupole Fiducialization Beam Finder Wire Fiducialization Complete Component Installation and Alignment on Girder Earth Field Compensation Measurement in Tunnel Girder Installation and Pre-Alignment in Tunnel Complete Installation and Checkouts of WPM and HLS Undulator Segment Installation on Girder Girder Alignment with Portable WPM / HLS Continuous Component Position Monitoring through WPM and HLS Beam-Based Alignment Periodic Rebaselining to Correct for Ground Motion etc. Undulator Segment Tuning and Fiducialization (Establishes SUSA) Quadrupole Fiducialization Beam Finder Wire Fiducialization Complete Component Installation and Alignment on Girder Earth Field Compensation Measurement in Tunnel Girder Installation and Pre-Alignment in Tunnel Complete Installation and Checkouts of WPM and HLS Undulator Segment Installation on Girder Girder Alignment with Portable WPM / HLS Continuous Component Position Monitoring through WPM and HLS Beam-Based Alignment Periodic Rebaselining to Correct for Ground Motion etc.

39. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 39 Conventional Alignment Tolerance Overview Tolerances for Girder Alignment in TunnelValueUnit Initial rms uncorrelated x/y quadrupole alignment tolerance wrt straight line100µmµm Initial rms correlated x/y quadrupole alignment tolerance wrt straight line300µmµm Longitudinal Girder alignment tolerance±1±1mm Undulator Segment yaw tolerance (rms)240µrad Undulator Segment pitch tolerance (rms)80µrad Undulator Segment roll tolerance (rms)1000µrad Component Monitoring and Control ToleranceValueUnit Horizontal / Vertical Quadrupole and BPM Positions±2±2µmµm Tolerances for Component Alignment on GirderValueUnit Horizontal rms alignment of quadrupole and BPM to Segment (rms)125µmµm Vertical rms alignment of quadrupole and BPM to Segment (rms)60µmµm Horizontal rms alignment of BFW to Segment (rms)100µmµm Vertical rms alignment of BFW to Segment (rms)55µmµm

40. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 40 The X-ray-FEL puts very tight tolerances on magnetic field quality, electron beam straightness, and Segment alignment. Alignment tolerances from electron beam straightness requirements can not be achieved with conventional alignment but require Beam Based Alignment (BBA) Procedure. Main task of conventional alignment and motion systems are SUSA determination and fiducialization Alignment of undulator segments (relative to adjacent quadrupole centers) Conventional alignment as prerequisite for BBA Provision of remotely controlled motion capability to support, alignment processes Monitoring of component positions in the presence of ground motion etc. Requirements and Specifications are available from the LCLS WEB site. The main Physics Requirements Document (PRD) outlining the requirements for the undulator system is PRD1.4-001. The X-ray-FEL puts very tight tolerances on magnetic field quality, electron beam straightness, and Segment alignment. Alignment tolerances from electron beam straightness requirements can not be achieved with conventional alignment but require Beam Based Alignment (BBA) Procedure. Main task of conventional alignment and motion systems are SUSA determination and fiducialization Alignment of undulator segments (relative to adjacent quadrupole centers) Conventional alignment as prerequisite for BBA Provision of remotely controlled motion capability to support, alignment processes Monitoring of component positions in the presence of ground motion etc. Requirements and Specifications are available from the LCLS WEB site. The main Physics Requirements Document (PRD) outlining the requirements for the undulator system is PRD1.4-001. Conclusions

41. Physics Requirements – October 20, 2005 Heinz-Dieter Nuhn, SLAC / LCLS Internal LCLS Undulator Alignment and Motion Review Nuhn@slac.stanford.edu 41 End of Presentation