1. Experience Fabricating the Storage Ring Vacuum Chambers for NSLSII
Prepared by: Charles Hetzel
July 12th, 2011

2. Facility and Cell Overview. Pumps and Valves.
Outline
Facility and Cell Overview.
Pumps and Valves.
Instrumentation and Absorbers.
RF bellows.
Chamber Cross Sections and Fabrication.
Chamber Assembly and Production Status.
Vacuum Instrumentation Rack Overview.

3. 30 cells (DBA) in 5 pendants Ring circumference: 792m 6
Facility Overview
Nominal energy: 3GeV
Nominal current: 500mA
30 cells (DBA) in 5 pendants
Ring circumference: 792m 6 5 6 6 4 3 1
1- Accelerator Tunnel
2- Experimental Floor
MeV LINAC
4 - Booster (C=158m)
5 - RF Building, liquid He Plant
6 - Service Buildings
5 pendants
30 cells
LINAC
booster 2 6 6

4. Short straight section
Typical Cell Layout
Each section of the cell is composed of girders assemblies.
3 focusing and 2 bending segments (DBA).
Alternating long and short straights (9.3m and 6.6m).
Photon extraction takes place at S3 and G6.
The ring is divided into 60 vacuum sections.
Sectors can be isolated with RF gate valves.
Design pressure (beam on): 10-9 torr.
ID photon extraction
Dipole and 3PW
photon extraction
Extraction points
Gate valves S2
Multipole S3
Dipole S4
Multipole S5
Dipole
Fast corrector S6
Multipole
Long straight section
RF gate valve
3 pole wiggler (3PW)
Short straight section
RF gate valve

5. 100 l/s ion pump TSP cartridge Turbo pump cart 18 units
Typical Cell Layout – Pumps
100 l/s ion pump
TSP cartridge
Turbo pump cart
18 units
NEG strips (St707)
1500m
Turbo cart rough pump
Ion pumps over absorbers (large gas load due 2 sync rad)
St707 SAES Getters
Distributed NEG pumping
200 l/s ion pump (8” or 6”)
TSP cartridge
Right angle valve

6. All metal gate valves used in transport lines and font ends.
Typical Cell Layout – Valves
All metal RF gate valves isolate cells and ID straights.
Double position indicators (to vac PLC and to EPS PLC).
Radiation resistant and bakeable.
Two first articles received.
Additional RF gate valves used to isolate SC cavities.
All metal gate valves used in transport lines and font ends.
Right angle valves
Rough pumping.
Instrumentation isolation.
RF gate valve
62 units
All metal GV - DN100
4mm bow 2mm gap
Returned to VAT for investigation
All metal gate valve
40 units
Right angle valve
270 units

7. Gauge tree with isolation valve.
Typical Cell Layout – Instrumentation
Instrumentation located in dipole chambers.
CCG and RGA in S3
CCG and TCG in S5
Gauge tree with isolation valve.
Typically scan and trend
7 on the 11

8. Intercepting surfaces are made GlidCop Al15.
Typical Cell Layout – Absorbers
Absorbers intercept unused dipole fan radiation.
Intercepting surfaces are made GlidCop Al15.
Stick absorber
20mm, 22mm, 25mm
130 units
< 700W (< 5 W/mm2)
Glidcop: 130°C, Tube: 119°C
Flange absorber
21mm X 64mm
90 units
< 200 W (< 16 W/mm2)
Most 25mm, 20mm for DW and RF
Zero opening crotch
90° knife edge
Crotch absorber
21mm
60 units
< 1800W (< 57 W/mm2)
GlidCop: 180°, Tube: 127°C

9. Angular deviation: +/-10 mrad Low impedance
RF Shielded Bellows
Water cooled flange
Requirements:
Misalignment: +/- 2 mm
Stroke: +10/-15 mm
Angular deviation: +/-10 mrad
Low impedance
Sleeve
(316L)
Bellows weldment
(316L)
RF fingers
(GlidCop)
Coil spring
(Be-Cu)
Contact springs
(Inconel 718)
Outside finger design (SPEAR 3)
Weldment purchased
BNL
Finger retainer
(316L)
Storage ring will require ~ 220 units
100 piece order in process
Weldment purchased, BNL

10. Fast corrector section
Vacuum Chambers
Multipole cross section
Dipole cross section
Almost all aluminum extrusion with bimetal flanges
3 channels extruded into the profile (cal rod)
Fast corrector inconel sheet 1mm thick.
Beam channel and the ante chamber extraction slot
S4A cross section
Fast corrector section

11. Only 2 vendors were willing and able to produce our extrusion.
Extrusion fabrication – Mutlipole and Dipole
Only 2 vendors were willing and able to produce our extrusion.
180 multipole extrusions.
140 dipole extrusions.
Extrusions were fabricated over ~18 months.
Incoming extrusions were inspected.
Dipole chambers.
Bent into shape.
Thermally cycled.
Re-measured.
Packaged and shipped for machining.
Large size (12.5” x upto 240” long) and the weight (~16#/ft)
Low volume and the challenging tolerance (features but the straightness and twist requirement)
2 vendors one MP one DP
All extrusions have been received.
Dipoles required quite a bit more work.
Bent using a press brake
Thermally cycled to relax the extrusions before machining

12. Support to prevent collapse Several cycles per extrusion
Dipole bending
Support to prevent collapse
Several cycles per extrusion
Everyone bent different
Bent to accommodate 6° angle in dipole
Success rate improved dramatically (~80%)

13. 2 machine shops were qualified Close vicinity to Argonne
Chamber Machining
2 machine shops were qualified
Close vicinity to Argonne
Mounting feature machined with the rest of the chamber.
Hi-Tech used some cleaver fixturing (losing registration)
Walco machined the entire part in one setup.
(167” [4.2m] x 108” [2.7m] x 56” [1.4m] 33,000#)

14. Welding of flange-adapter sub assemblies. Out of tolerance flanges.
Chamber Welding at Argonne
Welding of flange-adapter sub assemblies.
Out of tolerance flanges.
Sub assemblies to chamber welding.
Bake out and vacuum certification.
Leaky flanges (21 flanges, 10 chambers)
Currently producing 10 chambers per month.
All welding done at Argonne National Lab
Critical tolerances, problems with Atlas flanges, leaky flanges
Flange – transition sub assembly
Sub assy to chamber (S6 exit port to chamber)
Additional side ports, water fittings
After welding, chambers cleaned, instrumentation and pumps.
Bakeout and conditioning
Vac certification prior to shipment
Note: Pictures taken at Argonne National Laboratory

15. Flange ~ 70°C End adapters ~ 90°C
Chamber Welding
~ 8”/min
A-joint = minutes
Exit port = minutes
Flange ~ 70°C End adapters ~ 90°C
All welds single pass except for pump ports

16. Target Avg. Measured Values
Dipole Measurements
Measurement description
Target
Avg. Measured Values
Absorber flange to beam center
290.6mm
/- 1.5mm
Flatness of machined surface
+/- 1mm
+/- .6mm (1.8mm max)
Flange angle perpendicular to the orbit plane
9 mrad max
+/- 3 mrad (7 mrad max)
Transition flange twist
+/-3 mrad (7 mrad max)
Minimum wall thickness in machined area
3mm
2.5mm (1.9mm min)
After the chambers are welded and returned to BNL
Measure and confirm that they meet our requirements.

17. Target Avg. Measured Values
Multipole Measurements
Measurement description
Target
Avg. Measured Values
Absorber flange to beam center
252.0mm
/- 1.4mm
Chamber flatness near magnet pole cut outs
+/- 1mm
+/- .56mm (1.4mm max)
Flange angle perpendicular to the orbit plane
9 mrad max
+/- 3 mrad (10 mrad max)
Transition flange twist
+/- 5 mrad (6 mrad max)
Exit port survey point X
332.2mm
/- 1.5mm
Exit port survey point Y
7.1mm
7.1 +/- .5mm

18. BPM rf shield NEG assembly Bake out and conditioning Cal rod heater
Chamber Assembly
BPM
rf shield
NEG assembly
Bake out and conditioning
Cal rod heater
Currently assembling 10 chambers/month
Assembly work performed in class 1000 clean room (Clean room picture)
Install gauge tree (RGA, CCG) and small 20lps ion pump.
Bake out (cal rod): Leak check, bake 150°C for 6 hours
Activate NEG (50A for 2 min, 35A for 20 min). Valve off turbo when P <10-8
RGA scan for 12 hours to confirm gas species are stable.
(Ozone treatment if necessary) Bleed up with N2 and seal.
Ozone 400ppm in oxygen at 70°C for 6 hours.
Ultimate pressures of low 10s – high 11s torr.

19. 400ppm ozone in oxygen @ 70°C for 6 hours.
Ozone Treatment
Removal of surface contamination.
400ppm ozone in 70°C for 6 hours.
NEG activation 35 C.
Cool down and reprocess.
Treatment performed on 9 out of 90 chambers.
P = 1.3 x 10-9 Torr
3X bake 6 C.
P = 8.5 x Torr
Proven to be very effective

20. Chamber Ordered Machined Welded Assembled
Production Status – Multipole and Dipole Chambers
Chamber
Ordered
Machined
Welded
Assembled S2 34
32 (94%)
30 (88%) S4 33
18 (54%)
16 (47%) S6
24 (71%)
12 (35%)
35 mm Dipoles 62
62 (100%)
36 (58%)
27 (44%)
Totals
163
136 (83%)
98 (60%)
85 (52%)

21. Install after magnet pre-alignment (100µm).
Girder Integration
Install after magnet pre-alignment (100µm).
BPMs positioned using laser tracker (mechanical center).
Adjustment may be required after magnetic alignment (30µm).
Pumps and bake out wiring added after final alignment.
Final leak check and vacuum signoff.
Mechanical centers pre-aligned w Hamar laser
Next magnets split so the vac chamber can be installed.
Pre installed vibrating wire tube
Survey uses laser tracker to position the BPM to mechanical center
BPM position did not change when fixtures were removed.
Magnets are closed environmental room for magnetic alignment.
Depending on adjustments chamber may need to be repositioned
Final positions of BPMs stored in survey file.
Pumps (ion and TSP), bake out wiring, final leak check and signoff.

22. Three racks/cell located on mezzanine
Vacuum Instrumentation Rack Overview
Three racks/cell located on mezzanine
IPPS, TSP power supplies
Gauge controllers (CCG, Pirani)
PLC chassis, MOXA
Cables: Low smoke, zero halogen, tray rated
Computer system w touch screen

23. Gao-Yu Hsiung and June-Rong Chen (NSRRC)
Acknowledgments
Joe Gagliano, George Goeppner (APS)
Vacuum techs
C. Longo
S. Sharma
L. Doom
V. Ravindranath
T. Dilgen
B. Kosciuk
Gao-Yu Hsiung and June-Rong Chen (NSRRC)
Many others in and out of NSLS-II