1 BROOKHAVEN SCIENCE ASSOCIATES Production of Vacuum Components H.C. Hseuh NSLS-II ASAC Review...
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Transcript of 1 BROOKHAVEN SCIENCE ASSOCIATES Production of Vacuum Components H.C. Hseuh NSLS-II ASAC Review...
1 BROOKHAVEN SCIENCE ASSOCIATES
Production of Vacuum Components
H.C. HseuhNSLS-II ASAC ReviewOctober 14-15, 2010
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Outline
• Storage Ring Vacuum Chambers• Vacuum Parameters and Cell Layout• Aluminum chamber cross sections• Chamber fabrication and assembly
• Absorbers, S4A and RF Bellows • Absorber locations, design and prototyping• S4A stainless chamber and absorbers• RF bellows design and prototyping
• Vacuum Pumps and Other Components
• Summary
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Vacuum Chambers
• Beam aperture – 25 mm (V) x 76 mm (H)
• Ante-chamber for pumping and photon exit
• Chamber straightness - < 1 mm / 5 m
• Tapers - 10:1 ratio; steps or cavities < 1 mm
• Precision alignment of BPMs: ± 0.2mm (H) and ± 0.1mm (V)
• Discrete absorbers for BM fan
• Clear aperture for ID fan toward front end
P(avg) < 1 nTorr• (beam-gas) > 40 hrՇ
• no pressure bumps at straight sections➾ minimize bremsstrahlung radiation and shielding for BL
• Fast conditioning after intervention• In-situ bakeout to 130oC, NEG strip pumping• η (PSD) < 1 x10-5 molecules/hv after 100 A.hr beam dosage
NSLS-II Vacuum Requirement
.
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Cell Vacuum Chamber Layout
BM Beamline
ID Beamline
L.S.
S.S.
S2 S3S4 S5
S6
Stainless chambers
S1
S1
• 191 aluminum chambers, 3 – 5.5 m long• Extrusion w ante-chamber• > 12 types (length, magnet cutouts, etc.)
• 60 stainless steel chambers (S4A and S5A)• 30 x 1.5 m after BM-A; 30 x 0.6 m for 3PW• 90 short inconel sections for fast correctors (FC)
• ID chambers: 6 DW, 1 EPU, 4 IVU, ….• Special ones for Diag, Inj., RF…
Dipole
Multipole
BLW BLW BLWBLW
BLW
BLW
S4AS5A
BM-ABM-B
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Dipole Chamber Cross Section
< 3 mm wall
Adequate V gap (~15 mm)Sufficient H width for SR fans Extrusion width of 320 mm Bending effortAdequate wall thickness after machining
ID / 3PW fan
Pump port Crotch absorber2 mm gap
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Multipole Chamber Cross Section
RF screenNEGBPM
CHM in SextupoleStick absorber
Pump port
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Chamber Extrusion and Bending
Extrusion bending ➾ ➾ machining ➾ cleaning ➾ welding assembly➾V #1,2 BNL V # 3 - 7 APS APS BNL
Only two vendors are interested Width, quantity and tight tolerance Straightness ≤ 1 mm / 5 m Cross sections to < 0.5 mm/5 m
InspectionMultipole
Bending at BNL50 ton press w 45 cm throat
3 m, 6o (ρ = 25m) accuracy to < 1.5 mm / 3m
before
after
Shims
Spacer
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Chamber Machining and Welding
Robotic welding at APS
Completed chamber
Vacuum certification
Bi-metal flanges
Machined extrusion
12 Dipole and 24 multipole chambers completed (~ 20%)
Adaptor plate
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Chamber Assembly and Testing at BNL• Extrusion to Weldment
• BNL Measure → bend → measure → bake → measure
• → machining vendors → APS for welding → vacuum certification → BNL
• → 905 for measuring ports for BPM, absorber, flanges…
• → 905 clean room for chamber assembly• Install RF screen, BPM buttons, NEG strips, absorber
• Install ion pump, gauge and roughing valve
• → 905 for vacuum certification• Bake 130oC, UHV certification
• Rogue mode measurement
• Remove ion pump and gauges; install vibration wire support tube
• → 902 annex for girder integration/magnet measurement
• → 905 for wiring, bake and certification• Assemble large ion pump/TSP, pump down and LC, bake to 130oC
• → 740 (SR tunnel) for installation and testing
Process developed
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Aluminum Chamber Production Status
• Extrusion machined: ~ 30%• Chamber welded: ~ 20%• Chamber assembled: ~ 6%• Chamber ready for integration: ~ 5%
• APS welding: < 8 chambers per month• Need >10 chambers per month
• BNL assembly and bake: 1-2 per wk• Increase to 3 per week to meet girder
integration / installation schedule
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Locations for BM Photon Absorbers
BM+3PW fans
ID fan(s)
Crotch absorber
Stainless pipe / absorber
Stick absorber
Short Straight Long
Stra
ight
5 Stick ABS, 2 Crotch ABS & 1 S4A ABS (+ 3 Flange ABS)
Stick absorber
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BM Photon Absorbers
Stick ABS
BM Absorber Position and Power
GlidCop 15 for ABS
Crotch ABS
PrototypesStick location & quant.
Crotch openings
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Re-design of AbsorbersAfter review of ABS on Sept 8-9:• Re-design stick and crotch ABS
• To improve cooling, reliability and corrosion resistance
• To make them easier to manufacture
• Add ~ 90 flange ABS to protect BLW from large beam deviation
Stick ABS w/ Stainless cooling tube
Day-1 Crotch ABS w/ Cu cooling tube
Crotch ABS w/ wide opening
APS Flange ABS
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S4A Stainless Chamber / Absorber
Stainless CHM & distributed ABS:
Multipole CHM is too narrow for ID fans
Limited hor. space for stick ABS
Impedance of flange ABS
Intercept ~ 500 watts BM fan at 1.5o
BM-A BM-B
Prototypes
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S4A Chamber Re-design - aluminumStainless prototypes were:
Difficult to manufacture – tapers, inconel, …
Welding zone at mid plane
Can’t protect BLW from large beam deviation
New design:
Add two flange absorbers
Relocate d/s bellows to u/s
Separate Inconel chamber for FC
Aluminum extrusion for S4A
No taper, easier to machine/weld
Meet dimension tolerances
2-3 month effort
Extruded Aluminum
Uniform cross section
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Chose outside finger design wide fingers
no brazing water cooling
RF Shielded Bellows
Inside fingers $$, simple
Outside fingersLower impedance, $$$
RequirementsMax mis-alignment: ± 2 mm Max extension: -15/+10 mm Max angle deviation: ±10 mradLow impedance ohmic loss, HOM heating
Two options
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Re-design of RF shielded bellows
• Six prototypes completed and tested• Electrical test OK; mechanical test w/ some dust• Beam test at APS gave high finger temperature
• Being re-designed after review on Sept 8-9• Reduce the number of components
• Combine sleeve and RF fingers at one end• Improve thermal/electrical contacts
• One sliding joint, fewer coil springs• Electroplating of fingers and sleeves
• Increase contact force on RF fingers• Multiple-prong springs
Modified design
Before
Before
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Vacuum Pumps• Ion pumps, 100 l/s (150) & 200 l/s (200)
• Order placed in Feb 2010, 20% delivered
• Dual ion pump controllers (200)• Order placed in June 2010, 10% delivered
• NEG strips w custom holes and supports (1500m)• All strips delivered, 10% assembled into chambers• 30% NEG power supplies purchased
• Titanium sublimation pumps (300)• Order placed in July 2010, 10 1st articles delivered
• TSP power supplies (270), 50 A x 13 V• PS from 3 vendors evaluated, order to be placed in Nov
• Turbopump stations – 8 available, 8 more being assembledPump procurements are ahead of scheduleAll contracts cover procurements for injectors, FE, BL ….
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Vacuum Valves and Gauges• RF gate valves (60) RFQ in process, place order in Nov
• FE gate valves (20) and fast shutters (10) – FY11
• Right angle valves (~ 270), vendor selected – FY11
• Vacuum gauges and controllers (100 GC sets) • Gauges and controllers from 4 vendors evaluated• Draft specification done, RFQ in Nov
• Residual gas analyzers (60) – FY11• RGA from several vendors are being evaluated, RFQ in 2011
• Bakeout controllers• One 24-zone done, and two 12-zone ones being assembled• Eight 24-zone are to be assembled by vendors
Contracts will cover procurements for Injectors, FE, BL….
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Vacuum Production Summary• Vacuum system design is ‘almost’ completed• Chamber production/assembly started w ~ 20% available
• Need to ramp up the production rates to meet schedule• Re-design and fabrication of S4A ‘aluminum’ chambers started
• Procurement of other vacuum components• Vacuum pumps are ahead of schedule• TSP PS, VG, GV to be placed in a month
• Absorbers and RF bellows are re-designed and prototyped• Following the recommendations from expert review on Sept 8-9• Needed by May 2011 for ring installation