BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Storage Ring Vacuum Systems H. Hseuh, Vacuum Group ASAC Review of NSLS-II July 17-18, 2008

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Outline Vacuum System Requirement and Layout Vacuum Chamber Design Prototype Chamber Fabrication Ray Tracing, Absorbers and Pressure Profiles Layout of Straight Sections for ID, Inj. and RF Development in Bellows, BPM Buttons, NEG Strip Support Development in In-situ Bake and Ozone Cleaning Summary

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Vacuum Chambers - Adequate Apertures and Low Impedance Beam aperture – 25 mm (V) x 76 mm (H) Chamber straightness - < 1 mm / 5 m Smooth cross section changes: inclination angle < 10 o Minimum steps or cavities < 1 mm Mechanical stability: 1 fixed & 2 flexible invar supports at BPMs P(avg) 50% H 2, < 50% CO, CO 2, CH 4, …), Շ (beam-gas) > 40 hr (inelastic scattering) Local pressure bumps ➾ bremsstrahlung radiation Intercept BM photons at discrete absorbers –To protect un-cooled flanges and bellows –Large ion pump and TSP (or NEG cartridge) at absorbers Two NEG strips in antechamber to provide linear pumping Vacuum Requirements

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Cell Vacuum Chamber Layout BM Beamline ID Beamline L.S. S.S. Absorbers/pumps S m S3 - 3m S4 – 3.3m S5 – 3m S6 – 3.7m Aluminum Cell Chambers S2S3 S4 S5 S6 Multipole chamber Dipole chamber, 6 o bend Stainless chambers S1

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Extruded cross section Machined at pole locations Bended and machined Extruded 3 mm wall 3.1 mm wall Multipole Chamber Dipole Chamber At Quadrupole At Sextupole Cell Chamber Cross Sections and Analysis Maxi. δ = 0.3 mm x2 Max. S = 42 MPa Maxi. δ = 0.27 mm x2 Max. S = 64 MPa S yield (A6063T5) = 145 MPa S stress (A6063T5) = 186 MPa

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 End plate & bi-metal flanges Aluminum Cell Chamber Fabrication Extrusion ➾ bending ➾ machining ➾ cleaning ➾ welding ➾ assembly …. $ $$$ $ $$ $ V #1,2V #3V #4, 5, 6…APS BNL Extrusions Machining Test extrusion with two vendors completed Fabricate two S4 chambers by Sept Machining by CS and by vendor started Weld development by APS started Bending of dipole extrusions starts soon Machining End plate End Assy Welding at APS L. Doom

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Ray Tracing of Photon Fans To define photon fans and absorber locations ➾ To ensure adequate apertures for photon fans ➾ To protect un-cooled flanges and bellows ➾ To estimate power, density and ΔT for absorbers, and P profile Damping Wiggler Multipole Dipole Multipole DW fan DW absorber Flange absorber Stick absorber Crotch absorber DW fan : 32 kW x 2, ± 2.6 mrad canted by ± 1.8 mrad EPU fan: 6 kW x 2, ± 0.46/0.77 mrad canted by ± 0.12 mrad? IVU fan: 8 kW, ± 0.31 mrad Dipole fan : 2.4 kW, 105 mrad Damping Wiggler

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 DW and BM Photon Fans at S1-S4 Region Larger bellows and RF fingers to accommodate canted DW fan S2S3 S2 S3 DW ABS > 15 kW Vertical fan hitting Top/bottom wall BM S3, S6 ~5 EPU S1-S3 < 35 IVU20 S1 160* DW S1 166 S2 280 S3 270 S4 Source Location P(W) Large SR power intercepted here Limited space for pumping ports and multipoles S3 S4BS4A *on magnet shields M. Ferreira

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 P = 166 W P = 274 WP = 230 W S1B Simulation of DW vertical power using SPECTRA8 S2 S3 DW 1 P = 40 W From DW1 From DW2 DW 2 ΔP < 0.3 W/cm 2 h ~ 9 mm h = mmh = mm P = 6 W DW fan profile M. Ferreira Power and density are not excessive for S2 and S3 chambers Flange absorbers may be added at S1A-S1B, S1B-S2, and S2-S3? to trim vertical fan effectively, still with reasonable impedance mrad mrad ΔP < 0.5 W/cm 2 S1A

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Photon Absorbers (8-10 per cell) Stick < 12 W/mm 2, T max ~ 200 o C < 3 W/mm 2, T max ~ 68 o C P (kW) absorber22 P max (W/mm 2 )25 S max (MPa)303 T max ( o C)256 Damping Wiggler Absorber BM Absorber Positions and Power Crotch in dipole Crotch Stick in multipole Flange Absorber brazing development started

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Absorber Positioning vs. Aperture Requirement -- ± 3% aperture Δ ABS +X position W. Guo

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Pressure Profile with and without DW 3 GeV, 0.5A, η = 1x10 -5 P avg = 0.13 nT P avg = 0.25 nT LS SS Local ΔP w/ 15% DW fan ➾ bremsstrahlung radiation Molflow Code (R. Kersevan/ESRF) To be updated E. Hu

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Layouts for Insertion Device Straights ID Chamber Design: Chamber inner height ≈ magnet gap - 3 mm Extruded Al with NEG strips in antechamber Or extruded Al w/NEG coated APS ID chamber Limited space for stand-alone ID BPMs h = 8 x 57 mm, 1mm wall h = 7.5 mm, 1.25 mm wall ESRF NEG coated chamber 9.3 m straight for 2 x 3.5 m DW 6.6 m straight for 2 x 2 m EPU

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Injection Straight RF Straight Bellows + transition Layouts for Injection and RF Straights Working closely with AP, Diag, Magnet and other systems on the layout of special components

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 inside fingers M. Ferreira outside fingers Choice of RF Shielded Bellows inconel springs Be-Cu fingers Inside fingers Outside fingers (APS, LNLS) (Soleil, Diamond, etc) Simple, reliable Lower impedance $$ $$$ Outside fingers Wider fingers Fewer fingers RF Bellows Requirements: Max mis-alignment: 2 mm; Max comp/extension: ± 12 mm; Max angle deviation: 15 mrad 3D model for impedance simulation Inside or outside fingers?  loss = 10 mV/pC Solid sleeve

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Impedance of Other Vacuum Components Component #  loss, V  loss, V RF Bellows2001e-2?2 S4A pump port301e Stick absorber1202e Gate valve602e Crotch absorber60TBD Flange absorber~ 500.2? Multipole chamber with stick absorber and pumping ports S4A chamber with absorber and shielded pumping ports A. Blednykh GV RF shields Work closely with AP on vacuum components impedance simulation and approval Flange absorber S4A absorber and pump port Dipole chamber with crotch absorber and pumping ports

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Mounting of BPM Buttons/Flanges 7mm Ø 12 mm apart w/ 44 mm Ø flange Optimum design: 7 mm Ø buttons, 16 mm apart? (O. Singh’s talk) P. Cameron Rectangular flange? Sealing reliability? CD-2 Design 10mm Ø button /34 mm Ø flange /Helicoflex seal mm wall may be too thin for bolts/inserts & sealing 15 mm wall?

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 NEG strip supports Riveted mounting every 10cm, with alumina insulators on carrier plates Prototype to be tested on APS chambers for reliability and flexibility L. Doom, K. Wilson NEG support development using APS chambers NEG strips in Antechamber

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 M. Ferreira, F. Lincoln T ~120 o C achievable with foil heaters mounted at drift space (< 1 kW/m) Need to optimize power, heater temp, non-magnetic, insulation, etc Eliminate the needs of high P, hot water system, a major ES&H concern In-situ Bake with External Heaters APS chambers for bakeout development

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Process developed by T. Momose, KEK Final cleaning prior to installation (after alignment…) Extensive O 3 monitoring to meet ES&H requirements System being assembled for testing K. Wilson Ozone Cleaning Development Flush chamber with < 500 ppm O 3 in O 2 to break and remove contaminants Ozone system flow diagram

BROOKHAVEN SCIENCE ASSOCIATES SR Vacuum Systems ASAC Review, 7/17-18/ of 21 Summary Cell vacuum chamber design is well advanced Test extrusion of both cross sections completed with two vendors Machining and weld development of prototype chambers are underway Ray tracing and absorber development continues Straight section layouts for ID, RF and Inj has started RF shielded bellows design has started Work with AP on vacuum component impedanace Work with Diag. on finalizing BPM button/feedthru design. NEG strip supports developed and is being tested Chamber bakeout with foil heaters is successful Ozone cleaning system developed and is ready for evaluation