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1Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
Undulator Alignment StrategyHeinz-Dieter Nuhn, SLAC / LCLS
April 20, 2006
Undulator Alignment StrategyHeinz-Dieter Nuhn, SLAC / LCLS
April 20, 2006
Alignment Overview Alignment Tolerances Alignment Monitoring Correction Zones
Alignment Overview Alignment Tolerances Alignment Monitoring Correction Zones
2Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@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 includeGirder 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 includeSegment 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 includeGirder 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 includeSegment Fiducialization [SUSA wrt. Segment fiducials]
Quadrupole Fiducialization [Magnetic center wrt. Quad fiducials]
BFW Fiducialization [Wire location wrt. BFW fiducials]
3Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@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 CMMGirder-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 BBAFor 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 CMMGirder-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 BBAFor 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]
4Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
Girder Components Summary
Main girder components includeBeam Finder Wire (BFW)Undulator strongback arrangement mounted on horizontal slidesVacuum chamber supportBPMQuadrupoleMounts for the Wire Position Monitor (WPM) systemSensors 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 chamberSegments will be taken off the girder for magnetic measurementsSegments will be interchangeable without the need for the CMMThe complete girder assembly will be aligned on the Coordinate Measurement Machine (CMM).
Main girder components includeBeam Finder Wire (BFW)Undulator strongback arrangement mounted on horizontal slidesVacuum chamber supportBPMQuadrupoleMounts for the Wire Position Monitor (WPM) systemSensors 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 chamberSegments will be taken off the girder for magnetic measurementsSegments will be interchangeable without the need for the CMMThe complete girder assembly will be aligned on the Coordinate Measurement Machine (CMM).
5Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
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)
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)
Undulator QuadBFW
6Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
Undulator–to–Quad FiducializationTolerance Budget
Vertical Horizontal [µm] [µm] Quadrupole Fiducials Pulsed Wire Center Definition 10 10 Wire to Wire Finder (WF) Fiducial 20 20 WF Fiducial to Quadrupole Fiducial 10 10 25 25 Quadrupole BBA Offset 20 20 Undulator Fiducials Hall Probe Resolution/Positioning 20 20 Needle Hall Probe Resolution 15 30 Needle Center to Fiducial 20 30 Fixture Fiducial to Undulator Fiducial 20 20 40 50 Undulator Segment Roll-Away Repeatability 10 10 Alignment Quadrupole to Undulator 60 125 Grand Total [Beam-to-Undulator] 80 140
Individual contributions are added in quadratureIndividual contributions are added in quadrature
7Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
Undulator–to–BFW FiducializationTolerance Budget
Vertical Horizontal [µm] [µm] BFW Fiducials BFW Wire to Reference Stop 20 20 Reference Stop Definition 10 10 Reference Stop Fiducial 20 20 30 30 Undulator Fiducials Hall Probe Resolution/Positioning 20 20 Needle Hall Probe Resolution 15 30 Needle Center to Fiducial 20 30 Fixture Fiducial to Undulator Fiducial 20 20 40 50 X-Wire Positioning Repeatability - 80 Y-Wire Positioning Repeatability 30 - CAM Positioning Repeatability 4 4 Undulator Segment Roll-Away Repeatability 10 10 Alignment BFW to Undulator 55 100 Grand Total [Beam-to-Undulator] 80 140
Individual contributions are added in quadratureIndividual contributions are added in quadrature
8Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
Alignment Tolerance Summary
Tolerances for Girder Alignment in Tunnel 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
Undulator Segment roll tolerance (rms) 1000 µrad
Component Monitoring and Control Tolerance Value Unit
Horizontal / Vertical Quadrupole and BPM Positions (Depending on Zone) ±2 µm
Tolerances for Component Alignment on Girder Value Unit
Horizontal alignment of quadrupole and BPM to Segment (rms) 125 µm
Vertical alignment of quadrupole and BPM to Segment (rms) 60 µm
Horizontal alignment of BFW to Segment (rms) 100 µm
Vertical alignment of BFW to Segment (rms) 55 µm
9Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
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
10Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
Undulator Hall Network
dh = 50 μm
1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 2200 2250
UH Tunnel StartSTA 1672.09 ft509.653 m
SLOPE SLOPE
UH Tunnel WestSide Thermal BarrierSTA 2237.33 ft681.939 m
Undulator Hall Tunnel
BTH
BeamDump24” 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
Monuments Tracker Positions
Tracker
11Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@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.
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.
12Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
Undulator Segment Supports
Fixed Supports
Horizontal SlidesSegment
Cam Movers
ManualAdjustments
Girder
Manual Adjustments
Vacuum Chamber Support
13Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
14Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@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 SensorsIn 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 SensorsIn 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*Transverse Locations Tracked by HLS and WPM
15Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
610 mm
240
280
Wire1
Wire2
Position Monitor
Component Position Monitoring Systems(Alignment Diagnostics System – ADS)
UltrasoundProbe
Fiducial
Reference surfaces
• Resolution < 100 nm in X & Y direction• Instrument Drift < 100 nm per day• Moving Range ±1.5 mm in X & Y direction• Accuracy 0.1 % 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
HLS 1 HLS 2
HLS 4 HLS 3Beam
pitch
rollheight
Ceramic plate
ElectronicSensing Electrode
eAir
eWater DWater
DAir
X and Y, can be measuredRoll, Jaw & Pitch can be calculated.
Pitch
Y Roll
Y, can be measuredRoll & Pitch can be calculated.
16Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
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.
84
375
130
200
20
0
50
260
90
265
102
550
60
470
80
720
93
245
25
60
Girder Girder
Girder
Strongback
HLS pots
WPM supports
2" Pipe
115
Quadrupole
Beam
WPM stay clear areaalong entire Undulator
Yellow parts = Interface of WPM & HLS to grider
H2O Level
155
50
55
M10
Wire Position Monitor & Hydro Level System Interface
SLAC / LCLSF. Peters
Version:
Engineering:
Revision:03/23/06
005
G. Gassner
Dimensions in Millimeter
M6M6
Dis
tan
ce t
o flo
or
140
0 m
m
170
245 245
360
562
17Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
Strategies for Controlling Component Motion
Girder motion will be caused byGround 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.
18Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
Zone 1Zone 1 (non-invasive correction) (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 2Zone 2 ( (tt > 1 hr, > 1 hr, PP//PP00 > 90%, non-invasive) > 90%, non-invasive)• Maintain component alignment based on ADSMaintain component alignment based on ADS
Correction Zones
Zone 3Zone 3 ( (tt > 24 hr, > 24 hr, PP//PP00 > 90%, non-invasive) > 90%, non-invasive)• Maintain component alignment based on ADSMaintain component alignment based on ADS• Possible x-ray pointing correctionPossible x-ray pointing correction
Zone 4Zone 4 ( (tt > 1 mo, > 1 mo, PP//PP00 > 75%, machine time) > 75%, machine time)• One iteration of BBA (<1 hr)One iteration of BBA (<1 hr)
Zone 5 (Zone 5 (tt > 6 mo, shut-down) > 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
19Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
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
BPMs QuadsBFWs
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)
20Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
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 areComponent 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 areComponent 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
21Undulator Alignment Strategy – April 20, 2006 Heinz-Dieter Nuhn, SLAC / LCLSFAC Nuhn@slac.stanford.eduNuhn@slac.stanford.edu
End of Presentation
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