1. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 1 The Extruded Aluminum Chamber…

2. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 2 Why the Aluminum Extrusion… Relatively fast and inexpensive We have experience Built more than than 40 extruded aluminum insertion device chambers used at APS Built extruded aluminum insertion device chambers in use around the world Bessy II, SLS, CLS, Desy TTF Minimal welding needed Only a small, simple TIG weld on each end to attach a bi-metal flange Aluminum surface provides high AC conductivity Magnetic permeability of the chamber not a problem No need for surface coating

3. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 3 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.

4. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 4 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.

5. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 5 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.

6. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 6 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.

7. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 7 Prototype 1 Results 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. 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.

8. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 8 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.

9. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 9 Prototype 2 Results The 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.

10. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 10 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.

11. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 11 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.

12. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 12 Vacuum Chamber Specifications A draft Engineering Specification Document (ESD) is written. Requirements are below. ParameterValueAchieved Thickness of chamber at aperture6.00 +.15/-.05 mm6.00 – 6.10 mm Aperture height5.00 ±.08 mm5.00 – 5.07 mm Overall flange to flange length3464.44 +0/-.20 mmNot 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 mm2.46 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 scanAll peaks ≤ 44 AMU Vacuum chamber material6063 aluminum

13. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 13 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.

14. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 14 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

15. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 15 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/cm 2. sec Comparable to unpolished extrusion RGA scans were also comparable to the unpolished prototypes

16. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 16 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

17. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 17 The Schedule… EventOriginal Completion Date Updated Completion Date Polishing of all extrusions12/07/0711/30/07 Machining of all extrusions4/21/08 Chamber Processing at ANL4/23/08 Ship Chambers 1-5 to SLAC1/23/082/1/08 1-6 Ship Chambers 6-10 to SLAC1/28/082/22/08 6-11 Ship Chambers 11-20 to SLAC3/10/083/14/08 11-22 Ship Chambers 21-30 to SLAC3/26/084/4/08 22-33 Ship Chambers 31-40 to SLAC4/25/084/29/08 33-40

18. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 18 The Cost… Cost ItemsUpdated 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

19. FAC10/07 October 30, 2007 Greg Wiemerslage Weimer@aps.anl.gov 19 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 ongoing 10 Chambers already partially polished