Undulator System Update
Facility Advisory Committee Review
April 7th and 8th 2005
Stephen Milton
Argonne National Laboratory
Advanced Photon Source
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Outline
Quick Overview
Project Management and
Administrative Items
Organization
Plan for the next 6 months
FAC Responses
Magnet Measurement
Facility
See Robert Ruland’s Talk in
breakout session 1 and J.
Sevilla’s breakout session 4.
FAC Review April 2005
Undulator System Update
Physics Topics
Magnet Support System
Status
Vacuum System
Diagnostics Status
Building Topics
Controls Status
System Integration Test
Stephen Milton
milton@aps.anl.gov
Undulator System Overview
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Undulator Organization
Undulator
Physics
Undulator System
CF Physics
J. Welch
H.D. Nuhn
System Manager
S. Milton
Chief Engineer/Deputy
G. Pile
Global
Schedule and
Integration
PMCS Support
R. Boyce
P. Mast (AIM)
F. Clark (ANL)
SLAC
Integration
Controls System
System Manager
B. Youngman
B. Dalesio
System Layout
Magnetic
Measurement
Magnets and
Supports
Vacuum and
Diagnostics
R. Ruland
M. White
D. Walters
TBD
FAC Review April 2005
Undulator System Update
Controls
J. Stein
Stephen Milton
milton@aps.anl.gov
Faces
Geoff Pile
ANL LCLS Chief
Engineer
Responsible for
overall undulator
system integration
and will act in the
role of my Deputy
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Faces
Sushil Sharma
Fixed Supports Engineer
Will be responsible for
the engineering and
delivery of the undulator
system fixed supports
Has already begun
coordinating with Jim
Welch
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Faces
Horst Friedsam
ANL/SLAC Survey
and Alignment Liason
Will coordinate with
Robert Ruland to
ensure all survey and
alignment needs of
the undulator system
are met
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
New Roles
Undulator Integration Engineer
(SLAC)
At SLAC Brad Youngman will
oversee daily integration issue for
the undulator system
Brad will report directly to Geoff
Pile and myself
For administrative purposes Brad will
also report to Mark, but ANL will have
the final say on what Brad should be
doing
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
New Roles
Controls
Bob Dalesio directs the overall LCLS Controls
effort; therefore,
Josh Stein will work directly with Bob to ensure
a robost integration of the overall LCLS controls
system
For administrative purposes Josh will still report to
me, but Bob will have final say in all controls issues
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
6 Month Look Ahead
BPM System
Build cold test prototype xband beam detector
Design receiver boards
OTR
Assemble and Test Prototype
Wire Scanner
Assemble and Test Prototype
Support/Mover System
Assemble and Test Prototype
1st Article Undulators
Maybe receive 1st articles
from assembly vendors
Fixed Supports
Finalize design and begin
procurement for testing
Vacuum Chamber
Finalize testing of
construction methods
Start building prototype
Project Management
It never Ends
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
FAC Responses
Cradle (Mover/Support) System Needs
Attention
In addition to Emil Trakhtenberg an additional
engineer, Jeff Collins, has been assigned to
work on the Mover/Support System
All parts for the prototype have arrived and it will
be assembled soon
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
FAC Responses
Trade-offs must be considered to decide
whether longer girders can improve
tolerance to ground motion
An engineer with experience in girder system
(Sushil Sharma) has been assigned to fully
develop the fixed support strategy and
engineering
He is going over all trade-offs and he is responsible to
make the decision, pending review, of the support
system used
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
FAC Responses
The FAC recommends that, if the gap/period is
changed, a new prototype is not necessary
We are not changing the gap or the period
Consider the use of feed-forward from temperature
measurement to adjust the undulator horizontal
position and control K
Although this has been discussed and the system is
certainly capable of responding in such a fashion, we
have not pursued it or tested it yet
Temperature readback of the undulator will be available
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
FAC Responses
The decision has been made to NOT hire a general contractor
responsible for delivering complete undulators. The consequences of
this decision (plans for control of final assembly) should be presented
The magnet design and engineering has been refined with ease and
simplicity of construction in mind
A statement of work is being written and will include a complete description
of the QA process to be followed
A QA person has been assigned to the project
A complete assembly procedure has been written and a video is being
made of the assembly process
Two assembly vendors will be chosen
Assembly vendors are being prequalified
The 1st article from each of the two vendors will be thoroughly measured
and tested before we will accept additional undulators
Frequent vendor visits will be made to the vendors to perform QA/QC
checks and complete assembly travellers will be required for each undulator
and component
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Magnet Measurement Facility
SLAC Scope
ANL will act in both mentoring and consulting
roles as the facility gets constructed and
commissioned.
See Robert Ruland’s talk for more details
Undulator Measurement/Fiducialization/In-Situ
Alignment : Breakout session 1 4:00pm
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Physics Issues
Break Lengths
AC Conductivity
What we did
What we decided
Radiation Calculations
Preliminary Results
Next Steps
FAC Review April 2005
Undulator System Update
Alignment
BPM Location
Undulator Sections
Wire idea
Feedback
Earth’s Field
Correction
Initial Basic
Commission Steps
Stephen Milton
milton@aps.anl.gov
Undulator Break Lengths
(Old Strategy) New Strategy
Characteristic Lengths
Length of Undulator Strongback (Segment):
Lseg = 3.4 m
Distance for 113 x 2p Phase Slippage:
L0 = (3.668 m) 3.656 m
Taking from HD
Nuhn’s FAC Talk
Distance for 2p Phase Slippage in Field Free Space:
Linc = lu (1+K2/2) = 0.214 m
Standard Break Lengths Used
Use parameter n to characterize different phase length choices
Ln = L0 - Lseg +(n-1)Linc
Use 2 Short Breaks Followed by 1 Long Break in n-Pattern
2 – 2 – 4 ([0.482 m – 0.482 m – 0.910 m]) [0.470 m – 0.470 m – 0.898 m]
Fine Tuning of Initial Break Length
Suggested by N. Vinokurov based on Simulations by R. Dejus and N. Vinokurov
using Linear Simulation Code, RON
Small length increases for first 3 break lengths
[0.045 m – 0.020 m – 0.005 m]
Total Undulator Length (from beginning of strongback 1 – end of strongback 33):
Lund = (131.59 m) 131.52 m
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
AC Conductivity
induced energy deviation
for round chamber
FAC Review April 2005
Undulator System Update
induced energy deviation
for flat chamber
Stephen Milton
milton@aps.anl.gov
AC Conductivity
What’s been done
Theory
Bane, Stupakov, Huang
Simulation
Fawley, Reiche, Emma
Measurements
Yu, Walters
What was decided
The beam sees Al
We use a flattened cross-section
We explore a variety of operating points during commissioning
There will be a much more complete description of what
has been done supporting our decision during beakout
session 1 of the FAC
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Radiation Calculations
OTR Screens
We are concerned that the radiation produced
by these screens when inserted into the beam
could damage the undulator
Bingxin Yang produced a set of conditions and
geometries that might be encountered and
provided these to the SLAC radiation physicisit
Alberto Fassò chose the condition that would
produce the most radiation and did simulations
of it using his program FLUKA
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Radiation Calculations
The data in the
literature seems to
suggest that
neutrons are most
responsible for the
degradation in
performance of the
permanent magnet
blocks.
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Radiation Calculations
Preliminary Results
Even with a 100 micron thick screen the simulation suggests that we
could operate at 14 GeV with 1nC and at 120 Hz for 10 days before
experiencing damaging demagetization
Real operations
We intend to use foils that are only a micron or two thick
We also plan to use the OTR screens only at low repetition rates
(~10 Hz) and they will never be left in while we analyze data
However
Magnetic fields were not included in the FLUKA simulations
A field map will be given to Fassò along with other improvements in
the geometry and operating conditions
The simulation will be done again with these improvements
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Undulator Alignment
Question: How do you ensure that both ends of the
undulator are on the desired line?
Beam-based alignment will be used to position the
quadrupoles
The quadrupoles are “locked” to the end of the undulator with
their magnetic centers aligned to the desired magnetic center of
the undulator
The determines one end of the undulator
New idea
Use a wire at the other end of the undulator that has two
positions: one out and one in to a fixed stop
The in position would be accurately aligned to the desired
magnetic center of the undulator
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Undulator Alignment
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Undulator Alignment
Before any BBA or wire alignment performed
After BBA: Quad, BPM and one end of the undulator aligned
After Wire Alignment: Both ends of undulator aligned
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Undulator Alignment
Wire Issues
How do you distinguish easily between the
electron beam and the x-rays
The beam will create an easily seen radiation shower
downstream or
You could first extract the undulators
Horizontal positioning is less critical than vertical
Would require a wire after each undulator
New idea
Needs some time to cook
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
BPM Location
Adjacent to the Quadrupole (SM)
If we believe the BPM absolutely then it could go on the
other end and be used to align the downstream end of
the undulator
No need to do this if we use the wire method
Advantages of being adjacent to the quadrupole
The quad locations are critical and the is no ambiguity with the
BPM adjacent
Following BBA and following quad strength massaging one will
have the offset (mechanical and electrical) of the BPM
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Earth Magnetic Field Compensation Strategy
Earth Magnetic Field along Beam Trajectory in Undulator
requires compensation.
Estimated strength 0.43±0.06 Gauss :
(0.18±0.03, -0.38±0.07,0.08±0.05) Gauss
Based on Measurements by K. Hacker.
(see LCLS-TN-05-4)
Compensation Strategy:
Position the Undulator on Magnetic Measurement Bench in same
direction as in Undulator Tunnel
Compensate Earth Field Component in Undulator in Shimming
Process
Scheduling Issues
FAC Review April 2005
Undulator System Update
Taken from HD Nuhn’s
FAC Presentation
Stephen Milton
milton@aps.anl.gov
Earth Magnetic Field Compensation
Adjustable Shim Concept
Risk arises from the lack of precise knowledge of the earth field in the tunnel at
the time of undulator segment tuning.
Considering mitigation strategy based on use of a small number of precisely
adjustable shims along each undulator.
One extra shim per segment will reduce phase error by factor 4.
Shims will be installed before undulator tuning, but adjusted before undulator
installation when field error has been determined.
Will not affect definition of magnetic center of undulator (Standard Undulator
Axis, SUSA, [see PRD 1.4-001 4.7])
Also Taken from HD Nuhn’s
FAC Presentation
Quad
Undulator
BPM
Quad
Undulator
BPM
Quad
Trajectory w/o Shim
Shim Position
FAC Review April 2005
Undulator System Update
Trajectory w/ Shim
Stephen Milton
milton@aps.anl.gov
Magnet and Support System Status
Undulator Magnets
Long Lead
Procurements
Strong team Lead by M.
White
Titanium Strongback
Cost increase
(Commodities Price)
Magnet Poles
Cost Decrease
(Simplification)
Magnet Blocks
Supports
Support Mover System
Prototype being
assembled
Measurement equipment
ordered
Expect late May early
June Testing
CAM Mover system test
Sliding stage
measurements
Fixed Supports
Magnet Assembly
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Und. Magnet: LLP, Ti Strongback
Status
Two Vendors Chosen
Cost higher than expected due to very rapid
increase in cost of metal commodities over the
last couple of years
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Und. Magnet: LLP, Magnet Poles
Status
One Vendor Chosen
Based on cost
This vendor also had experience
Cost came is less than what we originally
estimated
Due to simplification of the pole design
No ears
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Und. Magnet: LLP, Magnet Blocks
Status
RFP Delayed
Spent additional time refining the sorting plan in the
statement of work.
The successful vendor will be required to sort the magnet
blocks prior to shipment to the assembly vendor
Do not expect the delay to impact the assembly
schedule
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Und. Magnet: Assembly
Plan to go with external assembly vendors
A lot of thought has gone into simplifying the assembly to the point that
assembly can be done easily with simple training
How we will do it
A statement of work is being written and will include a complete description
of the QA process to be followed
A QA person has been assigned to the project
A complete assembly procedure is being written and a video is being made
of the assembly process
Assembly vendors are being prequalified
Two assembly vendors will be chosen
The 1st article from each of the two vendors will be thoroughly measured
and tested before we will accept additional undulators
Frequent vendor visits will be made to perform QA/QC checks
Complete assembly travellers will be required for each undulator and
component
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Und. Magnet: Support/Mover System
Prototype parts in and assembly beginning
Testing expected in May/June
CAM, Sliding Mechanism, etc.
FAC Review April 2005
Undulator System Update
E. Trahktenberg and J. Collins
Stephen Milton
milton@aps.anl.gov
Und. Magnet: Support/Mover System
Detail of Support/Mover System
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Und. Magnet: Support/Mover System
CAM Mover system
Other system
reconsidered
CAM mover still found
to be the method of
choice
Modifications made
Total CAM offset
reduced to 1.5 mm
Better gearbox
Better bearings
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Und. Magnet: Fixed Supports
Recent Change
ANL takes over scope of the fixed support system
Experienced engineer assigned to the fixed support
Sushil Sharma
In consultation with Jim Welch
Options being reconsidered
Past thinking has been to use granite supporting 3
undulators
Other ideas are also being explored
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Vacuum System
Changes
Beam Sees Aluminum
Al on SS
Study of relative permeability
“Flat” cross-section Construction
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Vacuum System
Curves on the right show the
effect of both linear and
nonlinear permeability on the
undulator field
-3
4.0x10
Waiting for accurate, calibrated
permeability meter
=1.1 Constant
=1.1 Nonlinear
-3
-3
2.0x10
-3
1.0x10
0.0
-3
-1.0x10
-3
-2.0x10
-3
-3.0x10
-3
-4.0x10
 = 1.1
15 mm x 5 mm chamber crosssection
0.000
0.002
0.004
0.006
0.008
0.010
0.012
Perturbation from 15mm (H) x 5mm aperture chamber.
Constant and nonlinear permeability.
=1.1 Constant
=1.1 Nonlinear
-4
4.0x10
-4
2.0x10
0.0
-4
-2.0x10
-4
-4.0x10
0.000
0.002
0.004
0.006
0.008
0.010
0.012
Z [m]
FAC Review April 2005
Undulator System Update
0.014
Z [m]
 B [T]
Expect SS relative
permeabilities of less than 1.01
Looks OK but we will be doing
more direct measurements to
prove this is OK
Perturbation from 15mm (H) x 5mm aperture chamber.
Constant and nonlinear permeability.
3.0x10
 B [T]
Build chamber out of SS coated
with Al
What about the relative
permeability?
Stephen Milton
milton@aps.anl.gov
0.014
Chamber Design
Start with SS Flat
Coat with Al
Bend to Desired U shape
Weld to Vacuum Strongback
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Vacuum Status
Issues to address
SS permeability test
All samples in hand and parts in shops
~1 Month samples ready for measurement
Check of welding, bending, and annealing effects
Survey Market for
Coating needs
Polishing needs
Fabrication
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Diagnostics Status
BPMs
Intraundulator Xray Detectors
Location
Plans
Prototype plans
Waiting for in-vacuum motion
tests
OTR Screens
Use
Capabilities
Based on APS Bunch
Compressor Design
Resolution
Prototype Timeline
Vendor claims they will works
Must pass APS tests first
Other
Charge Monitors
Cerenkov Monitors
“End-Of-Undulator” Diagnostics
Wire Scanners
Use
Rethinking need and use
Undulator End Alignment Wire
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Diagnostics Status: BPM
Location
At the Quad
Plans
Use X-Band RF BPM
Internal Dimensions SLAC
responsibility
External ANL Responsibility
Processing Electronics
In-tunnel RF front end mixer
Generic RF front end
Capable for both cavity
and stripline
A/D Converter
Team determined
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Diagnostics Status: BPM
Prototype Plans
Build 4 cavities
Machining done externally
Brazing done at SLAC or
externally
To be determined
Mount three on a rigid support
and test with beam
Beam tests to occur at
FFTB/SPPS
Closed in Mar. 06?
Fall back location will be the
APS PAR Bypass line
B. Lill
PC Gun beam with bunch
compression
Timescale
Will need 1 year
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Diagnostics: OTR Screens
Use
Beam distribution measurement along the length of the
undulator
Can be used for emittance measurement as twiss
parameter checks
Features
Commercial 2 inch lens tube, magnification adjustable
with change of lens
Integral tungsten shield
Stepper driven remote focus
Digital video camera, 30-fps at 1 MP, or 120 fps at
VROI (250L), programmable gain.
Manual iris control
5 to 10 micron resolution
Based on APS Bunch Compressor OTR Success
Prototype
Parts on order
Testing to occur in summer 05
FAC Review April 2005
Undulator System Update
BX Yang
Stephen Milton
milton@aps.anl.gov
Diagnostics: Wire Scanner
Based on SLAC design. Adapted for tighter space.
Features
Mounted on 6-inch flange
On-axis drive mechanism in air
Share space with other diagnostics (OTR and x-ray)
Wire card to adapt SLAC design
Test setup is being designed
J. Bailey, BX Yang
Actual use being re-examined
Might switch to the simpler 2 state end alignment wire (see earlier description)
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Diagnostics: OTR and WS testing
Measure wire scanner motion
accuracy
Calibrate step size and cross check
encoder outputs
Measure motion error in all three
directions
Study motion error with different
mounting orientation
Characterize OTR camera module
Calibrate pixel size
Measure optical resolution
Status
conceptual design in progress
In-Vacuum motors
Waiting for tests
Vendor claims good
Must pass APS standards
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Undulator Hall and Buildings
Equipment Halls
Cable Length Runs
Temperature Control
Tight tolerances
20 ± 0.2 C
Needed for undulators (K value)
To minimize thermal expansion problems
Max (Min) Average power +50W/m (-50W/m)
Max power fluctuations 5W/m
For more details
Go to Welch talk at Breakout session 4 of the FAC
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Undulator Hall and Buildings
Requirements/Desires
Equipment Halls
Keep heat sources out of the tunnel
Keep cable lengths to less than 150’
Provide for convenient service and
maintenance for all electronics
Additional Hole for future
extension if needed
Maximum Cable Length < 150’
FAC Review April 2005
Undulator System Update
6 Undulators served
per drill hole
Stephen Milton
milton@aps.anl.gov
Controls Status
Organization
B. Dalesio in charge of LCLS controls
J. Stein of ANL matrixed to Dalesio to ensure controls integration between
undulator needs and the overall LCLS controls system
Undulator Equipment Halls
A lot of work has been done to plan
Cable routing
Equipment halls needs
Rack locations and needs
Major Undulator Systems
Motion Control
CAMs, Horizontal Motion, Intercepting Diagnostics
Video
OTR System with up to 120 Hz frame capture rates
Controls Presentation
See J. Stein talk in breakout session 3 of the FAC for more details about the
undulator controls
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
Systems Integration Test
One Undulator Support Mover Tests
Plan to assemble all major components and systems to test fit and
operations
Use the 1st article undulator and prototype mover support system
Use a chamber mockup if a prototype is not available
Fall 05
Multi Undulator System Integration Tests
Build up a complete system with at least 2 undulators
Use 1st articles or prototypes for everything including fixed supports
Test overall assembly, fit, and systems
Winter 06
System Integrations Test Presentation
See M. Whites talk in breakout session 1 of the FAC for more details
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov
End of Presentation
FAC Review April 2005
Undulator System Update
Stephen Milton
milton@aps.anl.gov