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FAC10/07October 30, 2007
2 Greg Wiemerslage
Why the Aluminum Extrusion…
Relatively fast and inexpensive We have experience
Built more than than 40 extruded aluminum insertion device chambers used at APSBuilt extruded aluminum insertion device chambers in use around the world
Bessy II, SLS, CLS, Desy TTF
Minimal welding neededOnly a small, simple TIG weld on each end to attach a bi-metal flange
Aluminum surface provides high AC conductivityMagnetic permeability of the chamber not a problemNo need for surface coating
FAC10/07October 30, 2007
3 Greg Wiemerslage
The disadvantages…
The as-extruded aperture is not smooth enough to minimize wakefield effects.
The aperture must be polished to reduce Wakefield effects.
New methods of polishing had to be explored to reach an acceptable surface finish.
We have settled on an approach utilizing “abrasive flow machining” technology.
FAC10/07October 30, 2007
4 Greg Wiemerslage
Abrasive Flow Polishing…
Normally an abrasive media is pushed back and forth through a part through the use of a hydraulic ram.
Our extrusion is greater than 10x longer than they are used to pushing through. A custom built diverter directs the media out orthogonal to the hydraulic ram.A flange attaches our extrusion with the diverter, and the media then flows out through our extrusion and drops into a bucket.After some refinements, the process produces satisfactory results.
FAC10/07October 30, 2007
5 Greg Wiemerslage
Best test results compared to the acceptability table…
The average rms slope error of the internal aperture in both the X (transverse) and Z (longitudinal) directions should ideally fall within the green or yellow sections of the acceptability table.
The green, yellow, orange and red symbols on the chart on the right are from the acceptability table.Green is very desirable.Yellow is acceptable.Orange is not desirable.Red should be avoided.
The blue diamonds are our data points. The red circle is the average of our data points—within the realm of acceptability.
FAC10/07October 30, 2007
6 Greg Wiemerslage
Prototypes were built…
To test the viability and mechanical characteristics of the full length chamber we had two prototype chambers produced.
Both chambers were cleaned, baked, vacuum tested and mechanically measured.
The results were excellent.
FAC10/07October 30, 2007
7 Greg Wiemerslage
Prototype 1 ResultsAfter a learning curve, the chamber was able to be straightened to ±50µm.
We did find that adjustment screws must be located every 10” over entire length to achieve desired straightness.
After a learning curve, the chamber was able to be straightened to ±50µm.
We did find that adjustment screws must be located every 10” over entire length to achieve desired straightness.
Location 1 Chamber Straightness
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
es
s (
mm
)
Top
Bottom
Location 1 Chamber Straightness
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
es
s (
mm
)
Top
Bottom
Location 3 Chamber Straightness
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
es
s (
mm
)
Top
Bottom
Location 3 Chamber Straightness
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
es
s (
mm
)
Top
Bottom
Location 2 Chamber Straightness
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
es
s (
mm
)
Top
Bottom
Location 2 Chamber Straightness
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
es
s (
mm
)
Top
Bottom
FAC10/07October 30, 2007
8 Greg Wiemerslage
Prototype 1 Results, Cont’d
The chamber wall thickness fell within ± 50 µm.There was no appreciable change in chamber thickness within the accuracy of measurement between atmosphere and vacuum measurements.The calculated aperture height range = 50 µm.
The chamber wall thickness fell within ± 50 µm.There was no appreciable change in chamber thickness within the accuracy of measurement between atmosphere and vacuum measurements.The calculated aperture height range = 50 µm.
Chamber Wall Thickness at Aperture
0.400
0.420
0.440
0.460
0.480
0.500
0.520
0.540
0.560
0.580
0.600
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Top
Bottom
Chamber Wall Thickness at Aperture
0.400
0.420
0.440
0.460
0.480
0.500
0.520
0.540
0.560
0.580
0.600
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Top
Bottom
Aperture Height (Calculated)
5.000
5.010
5.020
5.030
5.040
5.050
5.060
5.070
5.080
1 2 3 4 5 6 7 8 9 1 11 1 1 1 15
Chamber Location
Atmoshpere
Vacuum
Aperture Height (Calculated)
5.000
5.010
5.020
5.030
5.040
5.050
5.060
5.070
5.080
1 2 3 4 5 6 7 8 9 1 11 1 1 1 15
Chamber Location
Atmoshpere
Vacuum
Vacuum Chamber Thickness
6.020
6.030
6.040
6.050
6.060
6.070
6.080
6.090
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Th
ickn
ess
at A
per
ture
(m
m)
Atmosphere
Vacuum
Vacuum Chamber Thickness
6.020
6.030
6.040
6.050
6.060
6.070
6.080
6.090
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Th
ickn
ess
at A
per
ture
(m
m)
Atmosphere
Vacuum
FAC10/07October 30, 2007
9 Greg Wiemerslage
Prototype 2 ResultsThe chamber was straightened to ±80 µm within 4 hours.Could get within ±50 µm or better with minimal added effort.
The chamber was straightened to ±80 µm within 4 hours.Could get within ±50 µm or better with minimal added effort.
Location 1 Chamber Straightness
-0.140
-0.120
-0.100
-0.080
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
ess
(mm
)
Top
Bottom
Location 1 Chamber Straightness
-0.140
-0.120
-0.100
-0.080
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
ess
(mm
)
Top
Bottom
Location 2 Chamber Straightness
-0.140
-0.120
-0.100
-0.080
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
ess
(mm
)
Top
Bottom
Location 2 Chamber Straightness
-0.140
-0.120
-0.100
-0.080
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
ess
(mm
)
Top
Bottom
Location 3 Chamber Straightness
-0.140
-0.120
-0.100
-0.080
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
ess
(mm
)
Top
Bottom
Location 3 Chamber Straightness
-0.140
-0.120
-0.100
-0.080
-0.060
-0.040
-0.020
0.000
0.020
0.040
0.060
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Str
aig
htn
ess
(mm
)
Top
Bottom
FAC10/07October 30, 2007
10 Greg Wiemerslage
Prototype 2 Results, Cont’d
The chamber wall thickness fell within ± 50 µm.There was no appreciable change in chamber thickness within the accuracy of measurements between the atmosphere and the vacuum measurements.The calculated aperture height range = 80 µm.
The chamber wall thickness fell within ± 50 µm.There was no appreciable change in chamber thickness within the accuracy of measurements between the atmosphere and the vacuum measurements.The calculated aperture height range = 80 µm.
Chamber Wall Thickness at Aperture
0.400
0.420
0.440
0.460
0.480
0.500
0.520
0.540
0.560
0.580
0.600
1 2 3 4 5 6 7 8 9 1 11 1 1 1 15
Chamber Location
Top
Bottom
Chamber Wall Thickness at Aperture
0.400
0.420
0.440
0.460
0.480
0.500
0.520
0.540
0.560
0.580
0.600
1 2 3 4 5 6 7 8 9 1 11 1 1 1 15
Chamber Location
Top
Bottom
Aperture Height (Calculated)
5.000
5.010
5.020
5.030
5.040
5.050
5.060
5.070
5.080
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Ap
ertu
re h
eig
ht
(mm
)
Atmosphere
Vacuum
Aperture Height (Calculated)
5.000
5.010
5.020
5.030
5.040
5.050
5.060
5.070
5.080
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Ap
ertu
re h
eig
ht
(mm
)
Atmosphere
Vacuum
Chamber Thickness
6.000
6.020
6.040
6.060
6.080
6.100
6.120
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Th
ickn
ess
(mm
)
Atmosphere
Vacuum
Chamber Thickness
6.000
6.020
6.040
6.060
6.080
6.100
6.120
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Chamber Location
Th
ickn
ess
(mm
)
Atmosphere
Vacuum
FAC10/07October 30, 2007
11 Greg Wiemerslage
Gap Tolerance Stack-up…
Chambers can be manufactured well within the specified thickness tolerance.Chambers can be installed within the 250 µm tolerance allocated for chamber thickness variation and installation error using a reasonable amount of effort and modified support system.
The allocation should be switched so manufacturing tolerance is smaller and alignment tolerance is larger.
Chambers can be manufactured well within the specified thickness tolerance.Chambers can be installed within the 250 µm tolerance allocated for chamber thickness variation and installation error using a reasonable amount of effort and modified support system.
The allocation should be switched so manufacturing tolerance is smaller and alignment tolerance is larger.
FAC10/07October 30, 2007
12 Greg Wiemerslage
Vacuum Chamber SpecificationsA draft Engineering Specification Document (ESD) is written. Requirements are below.
Parameter Value Achieved
Thickness of chamber at aperture 6.00 +.15/-.05 mm 6.00 – 6.10 mm
Aperture height 5.00 ± .08 mm 5.00 – 5.07 mm
Overall flange to flange length 3464.44 +0/-.20 mm Not Measured
Vertical straightness of the mounted chamber after alignment ± 0.050 mm
± .05 mm on chamber 1
± .08 mm on chamber 2
Beam stay-clear radius around the chamber aperture axis ≥ 2.3 mm 2.46 mm worst case
Average rms slope error goal of aperture in both longitudinal and transverse directions – best effort See table -
Average vacuum pressure < 10-6 Torr <5 x 10-7
RGA mass scan All peaks ≤ 44 AMU All peaks ≤ 44 AMU
Vacuum chamber material 6063 aluminum 6063 aluminum
FAC10/07October 30, 2007
13 Greg Wiemerslage
Prototype Vacuum Tests…
Neither Prototype Chamber had detectable leaks present with a sensitivity of better than 2.0 x10-10 mbar.l/sec
Pumping from only one end, with the gauges on the opposite end of the chamber, the ultimate pressure of the first prototype chamber was 4.7 x 10-7 torr.
Pumping from only one end, with the gauges on the opposite end of the chamber, the ultimate pressure of the second prototype chamber was 1.2 x 10-7 torr.
Therefore the average pressure within both was better than 5.0 x 10-7 torr.
FAC10/07October 30, 2007
14 Greg Wiemerslage
Prototype Vacuum Tests…
Separate tests were conducted on a piece of the polished extrusion in parallel with the mechanical tests on the unpolished prototype chambers
Polishing process introduced no contaminants that could not be removed by standard cleaning
FAC10/07October 30, 2007
15 Greg Wiemerslage
Outgassing test results of the polished piece…Pressure after baking was 7.9 x 10-9 torr Residual outgassing is calculated at 2.4 x 10-13 torr.l/cm2.secComparable to unpolished extrusionRGA scans were also comparable to the unpolished prototypes
FAC10/07October 30, 2007
16 Greg Wiemerslage
Other efforts continue…
The ESD is in review
The SOW for machining is signed off and part of the requisition
We have requested budgetary estimates for machining and begun writing requisitions
We have begun preparing our fabrication facility specifically for the LCLS chambers
Shipping crates have been ordered
FAC10/07October 30, 2007
17 Greg Wiemerslage
The Schedule…Event Original Completion
DateUpdated Completion Date
Polishing of all extrusions 12/07/07 11/30/07
Machining of all extrusions 4/21/08
Chamber Processing at ANL 4/23/08
Ship Chambers 1-5 to SLAC 1/23/08 2/1/08 1-6
Ship Chambers 6-10 to SLAC 1/28/08 2/22/08 6-11
Ship Chambers 11-20 to SLAC 3/10/08 3/14/08 11-22
Ship Chambers 21-30 to SLAC 3/26/08 4/4/08 22-33
Ship Chambers 31-40 to SLAC 4/25/08 4/29/08 33-40
FAC10/07October 30, 2007
18 Greg Wiemerslage
The Cost…Cost Items Updated Estimates and
Quotes…Oct 07
Extrusions $11,165.44
Flanges $41,310.00
Polishing Prep $350.00
Polishing $152,819.85
Straightening $15,600.00
Machining $238,400.00
Crating $4,979.60
Surface Sampling prep
$5,040.00
ANL labor ~$220,000
Total $689,664.89
So far Extrusion costs are within original (WAG)
estimates + contingency factor
FAC10/07October 30, 2007
19 Greg Wiemerslage
Progress to Date…
All Extrusions prepared for polishing and sent to Engineered Finishing Corporation (EFC)
Ends of extrusions are already machined to accept mating flange
Control samples of the first 54 un-polished extrusions were cut and sent for surface finish analysis
Polishing requisition awarded and polishing has begun
Polishing process is ongoing10 Chambers already partially polished
