Undulator Alignment Strategy HeinzDieter Nuhn SLAC LCLS April

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

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] Undulator Alignment Strategy – April 20, 2006 FAC 2 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

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] Undulator Alignment Strategy – April 20, 2006 FAC 3 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

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). Undulator Alignment Strategy – April 20, 2006 FAC 4 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

Beam Finder Wire (BFW) BFW 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) Vacuum Chamber BFW Wake Mitigation Undulator Quad Wires Beam Direction Undulator Alignment Strategy – April 20, 2006 FAC 5 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

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

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

Alignment Tolerance Summary Tolerances for Component Alignment on Girder Value Horizontal alignment of quadrupole and BPM to Segment (rms) Vertical alignment of quadrupole and BPM to Segment (rms) Horizontal alignment of BFW to Segment (rms) Vertical alignment of BFW to Segment (rms) Tolerances for Girder Alignment in Tunnel Unit 125 µm 60 µm 100 µm 55 µm Value Unit Initial rms uncorrelated x/y quadrupole alignment tolerance wrt straight line 100 µm Initial rms correlated x/y quadrupole alignment tolerance wrt straight line 300 µm Longitudinal Girder alignment tolerance ± 1 mm Undulator Segment yaw tolerance (rms) 240 µrad Undulator Segment pitch tolerance (rms) 80 µrad 1000 µrad Value Unit Undulator Segment roll tolerance (rms) Component Monitoring and Control Tolerance Horizontal / Vertical Quadrupole and BPM Positions (Depending on Zone) Undulator Alignment Strategy – April 20, 2006 FAC 8 ± 2 µm Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

Survey Monuments Extract from ESD 1. 4 -113 Undulator Tunnel Survey Monument Positions B. Fuss 1‘ stay-clear wall monuments (with removable spherical target) floor monument 6’ (with removable spherical target) Undulator Alignment Strategy – April 20, 2006 FAC 9 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

Undulator Hall Network BTH 1600 UH Tunnel West Side Thermal Barrier STA 2237. 33 ft 681. 939 m UH Tunnel Start STA 1672. 09 ft 509. 653 m 1650 1700 SLOPE 1750 1800 1850 1900 1950 2000 Undulator Hall Tunnel Monuments 2050 SLOPE 2100 2150 2200 24” Vertical Penetration (approx. position) 2250 Beam Dump Tracker Positions Quadruples Inputs: Results: Tracker s. D = 30 μm sh = 30 μm / D sv =50 μm /D Level sdh = 50 μm sz = 22 μm sx = 47 μm sy =46 μm Undulator Alignment Strategy – April 20, 2006 FAC 10 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

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. Undulator Alignment Strategy – April 20, 2006 FAC 11 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

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

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

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 *Transverse Locations Tracked by HLS and WPM Undulator Alignment Strategy – April 20, 2006 FAC 14 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

Component Position Monitoring Systems (Alignment Diagnostics System – ADS) Wire Position Monitor system (WPM) • • • Resolution Instrument Drift Moving Range Accuracy Availability < 100 nm in X & Y direction < 100 nm per day ± 1. 5 mm in X & Y direction 0. 1 % of full Scale Permanent, no interrupts X and Y, can be measured Roll, Jaw & Pitch can be calculated. Hydrostatic Leveling System (HLS) Capacitive Sensor • Precision < 1 mm • Instrument Drift ~1 -2 mm / month • Accuracy < 0. 1 % of full Scale Y Ultrasound Sensor • Precision < 0. 1 mm • Instrument Drift potentially no drift • Accuracy < 0. 1 % of full Scale Undulator Alignment Strategy – April 20, 2006 FAC 15 Roll Pitch Y, can be measured Roll & Pitch can be calculated. Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

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

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. Undulator Alignment Strategy – April 20, 2006 FAC 17 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

Correction Zones Zone 1 (non-invasive correction) • 120 -Hz traj-feedback (LTU BPM’s) • 0. 1 -Hz traj-feedback (und. BPM’s) Zone 2 (Dt > 1 hr, P/P 0 > 90%, non-invasive) • Maintain component alignment based on ADS mo Zone 3 (Dt > 24 hr, P/P 0 > 90%, non-invasive) • Maintain component alignment based on ADS • Possible x-ray pointing correction Zone 4 (Dt > 1 mo, P/P 0 > 75%, machine time) • One iteration of BBA (<1 hr) Zone 5 (Dt > 6 mo, shut-down) • Reset movers set to zero and manual realignment (1 wk) • Full 3 iterations of BBA (~3 hrs) Undulator Alignment Strategy – April 20, 2006 FAC 18 Heinz-Dieter Nuhn, SLAC / LCLS Nuhn@slac. stanford. edu

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

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

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