1. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 1 Undulator Alignment Strategy Heinz-Dieter Nuhn, SLAC / LCLS April 20, 2006 Alignment Overview Alignment Tolerances Alignment Monitoring Correction Zones Alignment Overview Alignment Tolerances Alignment Monitoring Correction Zones

2. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 2 Undulator Alignment Overview The focus of the undulator alignment is on Quadrupoles and Beam Position Monitors (BPMs) Beam Finder Wires (BFW) Undulator Strongbacks (Segments) The alignment procedures include Girder Component Alignment [checked on CMM] Conventional Tunnel Alignment Beam Based Alignment (BBA) [Energy Scan followed by BFW] Continuous Monitoring and Correcting of Component Positions Auxiliary alignment procedures include Segment Fiducialization [SUSA wrt. Segment fiducials] Quadrupole Fiducialization [Magnetic center wrt. Quad fiducials] BFW Fiducialization [Wire location wrt. BFW fiducials] The focus of the undulator alignment is on Quadrupoles and Beam Position Monitors (BPMs) Beam Finder Wires (BFW) Undulator Strongbacks (Segments) The alignment procedures include Girder Component Alignment [checked on CMM] Conventional Tunnel Alignment Beam Based Alignment (BBA) [Energy Scan followed by BFW] Continuous Monitoring and Correcting of Component Positions Auxiliary alignment procedures include Segment Fiducialization [SUSA wrt. Segment fiducials] Quadrupole Fiducialization [Magnetic center wrt. Quad fiducials] BFW Fiducialization [Wire location wrt. BFW fiducials]

3. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 3 Main Alignment Concepts Pre-alignment (baselining) uses the manual adjustments on top of the support structures. Relative alignment of Girder components is achieved and maintained through common-girder mounting checked by CMM Girder-to-Girder alignment is (remotely) controlled based on cam-shaft technology During initial alignment [with focus on quadrupole and BFW positions] For quadrupole position control, i.e. beam steering during BBA For compensation of ground motion effects etc. Beam-Based-Alignment uses quadrupole magnets in two ways: 1)via off-center dipole fields. [Change is done through cam-based girder motion, which will align all girder components to the beam. Minimum motion range covers area of circle with 700 µm radius ] 2)via dipole trim-windings on Quadrupole Magnets (used for fine adjustments.) [Range equivalent to ±100 µm of Quad motion] Pre-alignment (baselining) uses the manual adjustments on top of the support structures. Relative alignment of Girder components is achieved and maintained through common-girder mounting checked by CMM Girder-to-Girder alignment is (remotely) controlled based on cam-shaft technology During initial alignment [with focus on quadrupole and BFW positions] For quadrupole position control, i.e. beam steering during BBA For compensation of ground motion effects etc. Beam-Based-Alignment uses quadrupole magnets in two ways: 1)via off-center dipole fields. [Change is done through cam-based girder motion, which will align all girder components to the beam. Minimum motion range covers area of circle with 700 µm radius ] 2)via dipole trim-windings on Quadrupole Magnets (used for fine adjustments.) [Range equivalent to ±100 µm of Quad motion]

4. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 4 Girder Components Summary Main girder components include Beam Finder Wire (BFW) Undulator strongback arrangement mounted on horizontal slides Vacuum chamber support BPM Quadrupole Mounts for the Wire Position Monitor (WPM) system Sensors of the Hydrostatic Leveling System (HLS) 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 will be interchangeable without the need for the CMM The complete girder assembly will be aligned on the Coordinate Measurement Machine (CMM). Main girder components include Beam Finder Wire (BFW) Undulator strongback arrangement mounted on horizontal slides Vacuum chamber support BPM Quadrupole Mounts for the Wire Position Monitor (WPM) system Sensors of the Hydrostatic Leveling System (HLS) 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 will be interchangeable without the need for the CMM The complete girder assembly will be aligned on the Coordinate Measurement Machine (CMM).

5. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 5 Beam Finder Wire (BFW) Vacuum Chamber Wake Mitigation Wires BFW Beam Direction A misaligned undulator will not steer the beam. It will just radiate at the wrong wavelength. The BFW allows the misalignment to be detected. (also allows beam size measurements) UndulatorQuadBFW

6. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 6 Undulator–to–Quad Fiducialization Tolerance Budget Individual contributions are added in quadrature

7. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 7 Undulator–to–BFW Fiducialization Tolerance Budget Individual contributions are added in quadrature

8. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 8 Alignment Tolerance Summary 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 (Depending on Zone)  ±2 ±2 µmµm Tolerances for Component Alignment on GirderValueUnit Horizontal alignment of quadrupole and BPM to Segment (rms)125µmµm Vertical alignment of quadrupole and BPM to Segment (rms)60µmµm Horizontal alignment of BFW to Segment (rms)100µmµm Vertical alignment of BFW to Segment (rms)55µmµm

9. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 9 Survey Monuments wall monuments (with removable spherical target) floor monument (with removable spherical target) 6’ 1‘ stay-clear Extract from ESD 1.4-113 Undulator Tunnel Survey Monument Positions B. Fuss

10. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 10 Undulator Hall Network  dh = 50 μm 16001650 17001750180018501900195020002050210021502200 2250 UH Tunnel Start STA 1672.09 ft 509.653 m SLOPE UH Tunnel West Side Thermal Barrier STA 2237.33 ft 681.939 m Undulator Hall Tunnel BTH Beam Dump 24” Vertical Penetration (approx. position)  D = 30 μm  h = 30 μm / D  v =50 μm /D  z = 22 μm  x = 47 μm  y =46 μm Inputs: Results: Quadruples Level MonumentsTracker Positions Tracker

11. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 11 Undulator Alignment Controls Manual Adjustability: Rough CAM position adjustability relative to fixed support. ranges: x (12 mm); y (25 mm); z (12 mm) Quadrupole, BFW, BPM, Vacuum Chamber, and Segment adjustability to Girder. ranges: x (>1 mm); y (>1 mm); z (>1 mm) Remote Adjustability: Girder: x, y, pitch, yaw, roll [  1.5 mm x and y] Enables alignment of all beamline components to the beam axis. Roll motion capability is to be used to keep roll constant Undulator: x [ 80 mm range] Provides control of undulator field on beam axis. Horizontal slide stages move undulator strongback independent of Girder and vacuum chamber. Manual Adjustability: Rough CAM position adjustability relative to fixed support. ranges: x (12 mm); y (25 mm); z (12 mm) Quadrupole, BFW, BPM, Vacuum Chamber, and Segment adjustability to Girder. ranges: x (>1 mm); y (>1 mm); z (>1 mm) Remote Adjustability: Girder: x, y, pitch, yaw, roll [  1.5 mm x and y] Enables alignment of all beamline components to the beam axis. Roll motion capability is to be used to keep roll constant Undulator: x [ 80 mm range] Provides control of undulator field on beam axis. Horizontal slide stages move undulator strongback independent of Girder and vacuum chamber.

12. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 12 Undulator Segment Supports Fixed Supports Horizontal Slides Segment Cam Movers Manual Adjustments Girder Manual Adjustments Vacuum Chamber Support

13. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 13

14. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 14 Undulator Alignment Monitoring Elements Hydrostatic Leveling System (HLS) Monitored Degrees of Freedom are: y, pitch, and roll Wire Position Monitoring System (WPM) Monitored Degrees of Freedom are: x, (y), (pitch), yaw, and roll Temperature Sensors In support of HLS/WPM readout corrections, undulator K corrections, and component motion interpretation. Beam Position Monitors * Monitored quantities are: x and y position of electron beam Quadrupoles * Monitored quantities are: electron beam x and y offset from quad center Hydrostatic Leveling System (HLS) Monitored Degrees of Freedom are: y, pitch, and roll Wire Position Monitoring System (WPM) Monitored Degrees of Freedom are: x, (y), (pitch), yaw, and roll Temperature Sensors In support of HLS/WPM readout corrections, undulator K corrections, and component motion interpretation. Beam Position Monitors * Monitored quantities are: x and y position of electron beam Quadrupoles * Monitored quantities are: electron beam x and y offset from quad center * Transverse Locations Tracked by HLS and WPM

15. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 15 Component Position Monitoring Systems (Alignment Diagnostics System – ADS) Resolution< 100 nm in X & Y direction Instrument Drift < 100 nm per day Moving Range ±1.5 mm in X & Y direction Accuracy0.1 % of full Scale Availability Permanent, no interrupts Wire Position Monitor system (WPM) Hydrostatic Leveling System (HLS) Precision < 1  m Instrument Drift ~1-2  m / month Accuracy < 0.1 % of full Scale Capacitive Sensor Ultrasound Sensor Precision < 0.1  m Instrument Drift potentially no drift Accuracy < 0.1 % of full Scale X and Y, can be measured Roll, Jaw & Pitch can be calculated. Pitch Y Roll Y, can be measured Roll & Pitch can be calculated.

16. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 16 ADS…Common Sensor Support Quadrupole X & Y- Position will be measured relative to the references. Roll, Pitch, Yaw and Torsion of the Girder can be calculated.

17. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 17 Strategies for Controlling Component Motion Girder motion will be caused by Ground Motion Temperature Changes CAM Rotation Girder motion will be monitored in 2 ways. 1.Directly, through the Alignment Diagnostics System 2.Indirectly, through impact on electron beam trajectory (as detected by BPMs) Girder Positions will be frequently corrected using the CAM movers.

18. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 18 Zone 1 (non-invasive correction) 120-Hz traj-feedback (LTU BPM’s)120-Hz traj-feedback (LTU BPM’s) 0.1-Hz traj-feedback (und. BPM’s)0.1-Hz traj-feedback (und. BPM’s) Zone 2 (  t > 1 hr,  P/P 0  > 90%, non-invasive) Maintain component alignment based on ADSMaintain component alignment based on ADS Correction Zones Zone 3 (  t > 24 hr,  P/P 0  > 90%, non-invasive) Maintain component alignment based on ADSMaintain component alignment based on ADS Possible x-ray pointing correctionPossible x-ray pointing correction Zone 4 (  t > 1 mo,  P/P 0  > 75%, machine time) One iteration of BBA (<1 hr)One iteration of BBA (<1 hr) Zone 5 (  t > 6 mo, shut-down) Reset movers set to zero and manual realignment (1 wk)Reset movers set to zero and manual realignment (1 wk) Full 3 iterations of BBA (~3 hrs)Full 3 iterations of BBA (~3 hrs) mo

19. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 19 Undulator HallMMF Alignment Function Diagram Segment Tuning and Fiducialization Quadrupole Fiducialization BFW Fiducialization Component Alignment on Girder Environmental Field Measurement Girder Pre- Alignment ADS Installation Girder Alignment using ADS Loose End-Alignment Undulator Segment Installation Electron Beam-Based Alignment USE OF DIAGNOSTICS COMPONENTS Supports Alignment BPMsQuads BFWs Once per month: Swap 3 Segments Continuous Position Correction Once every 6 month: Re-baselining Every 2 – 4 weeks: Invasive Correction Segment Tuning ADS (HLS/WPM)

20. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 20 The X-ray-FEL puts very tight tolerances on magnetic field quality, electron beam straightness, and Segment alignment. These tolerances can be achieved through Beam Based Alignment (BBA) procedures based on BPMs and Quadrupoles (with energy scan) as well as BFWs. Relative component alignment to required tolerances will be achieved through common girder mounting. Main tasks of the conventional alignment and motion systems are Component fiducialization and alignment on girder Conventional alignment of girders in Undulator Hall as prerequisite for BBA The Alignment Diagnostic System measures and enables the correction of girder movement due to ground motion, temperature changes, and CAM mover changes. A strategy is in place for using the monitor systems and controls to establish and maintain a straight trajectory. The X-ray-FEL puts very tight tolerances on magnetic field quality, electron beam straightness, and Segment alignment. These tolerances can be achieved through Beam Based Alignment (BBA) procedures based on BPMs and Quadrupoles (with energy scan) as well as BFWs. Relative component alignment to required tolerances will be achieved through common girder mounting. Main tasks of the conventional alignment and motion systems are Component fiducialization and alignment on girder Conventional alignment of girders in Undulator Hall as prerequisite for BBA The Alignment Diagnostic System measures and enables the correction of girder movement due to ground motion, temperature changes, and CAM mover changes. A strategy is in place for using the monitor systems and controls to establish and maintain a straight trajectory. Conclusions

21. Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLS FAC Nuhn@slac.stanford.edu 21 End of Presentation