BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 SR Chambers & RF Bellows H. Hseuh, Vacuum Group ASAC Review of NSLS-II Mar 26-27, 2009

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Acknowledgements BNL: A. Blednykh, P. Cameron, C. De la Parra, S. DiStefano, L. Doom, M. Ferreira, E. Hu, F. Lincoln, C. Longo, S. Krinsky, V. Ravindranath, P. Settepani, S. Sharma, O. Singh, J. Skaritika, J. Sullivan, K. Wilson, …. ANL: J. Gagliano, G. Goeppner, … ESRF: R. Kersevan Diamond: M. Cox KEK: Y. Suetsugu SLAC: N. Kurita, M. Sullivan, L. Wang, U. Wienands, … TPS: J.R. Chen, G-Y. Hsiung, … and many others.

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Outline SR Vacuum Chambers and FY08 Effort –Material, quantity, types, fabrication –Extrusions w/ two vendors –Weld development of multipole chambers at APS Prototyping and Testing Effort in FY09 –Bending of dipole extrusions –Extrusion of new multipole cross section –Weld development at APS –Testing of NEG strips and cal rod heaters –Interface with Magnets, AP, Diag. etc RF Shielded Bellows -Design options and prototyping Recent Review Recommendations

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Cell Vacuum Chamber Layout BM Beamline ID Beamline L.S. S.S. S2S3 S4 S5 S6 Stainless chambers S1 60 stainless steel chambers, 1-2 m long 5 types (cross sections, length, flanges, etc) Stainless sheets, rolled, welded and brazed w/ Cu absorbers 191 aluminum chambers, 3 – 6 m long Extruded, two cross sections (dipole and multipole) > 12 types (length, magnet cutouts, flanges, etc.) Precision machining & welding to meet beam requirement Dipole Multipole

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 S3 S5 S3-DW 90mm S3 & S5 S2-DW S2E S2O S4 S6E S6O Multipole also for day-1 straight Dipole Cell Aluminum Chamber Types E: even cell; O: odd cell; DW: canted by ± 1.8 mrad

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 End adaptor Multi-step Fabrication of Al Chambers Extrusion ➾ Bending ➾ Machining ➾ Cleaning ➾ Welding ➾ Assembly… V #1,2 BNL BNL, V # 3,4,5. APS BNL Extrusions Machined extrusion Machined end End adaptors End assembly Bi-metal flanges Robotic welding at APS Pump port Lewis Doom

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Prototyping in FY08 Prototype multipole chamber for alignment, BPM mounting, NEG carriers and bakeout Test extrusions completed Fabrication process fully developed for ‘old’ multipole chambers 4mm X15 Micrographs of welds show Full fusion, no micro cracks No void and trapped gas Step ≤ 0.5 mm X50 APS/ANL

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of ton press break with 18-inch throat W/ garnet filler, w/o filler Change punch heights and load distributions – curvature to within 1 mm Little spring back w/ thermal cycling to 180C Gap reduction by 1 – 2.5 mm Bending of Dipole Extrusion at BNL BNL CS break Spread the load outboard from the center will give more bending toward the ends. Fine tweaking the punch & shimms to get the exact bend! Lewis Doom Phil Settepani

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 New Multipole Extrusion & Weld Development Test extrusion orders placed To be completed by May Increase wall from 12 to 16 mm for improved BPM dual buttons/flange New New BPM flange Old Short dipole chambers and flanges Multipole extrusion w/ exit port cutout Welding development at APS dipole, new multipole & exit port A multi-yr contract w/ APS is in place CD-2 Design

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 NEG Strips and Carriers NEG carriers and feedthru NEG strips in antechamber Two NEG strips in each aluminum chamber as main distributed pumping – total ~ 1,200m Riveted mounting every 10 cm w/ ceramic insulators and carrier plates Fully tested in prototype chambers Modified carriers for BPM TE modes? Activation at C x 30 min with 70 A thru NEG strips Feedthru Lewis Doom Phil Settepani

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 FY09 – One Cal rod heater (10 mm φ) inserted in unused cooling channel > 120 C and ΔT < 5 C simple & versatile – to be tested for easy of installation and reliability In-situ Bake with External Heaters Baseline design: 135 o C x 150 psi water (as in APS and Spring-8) A major ES&H concern FY08 - T < 150 o C achieved with foil heaters and insulation attached to limited magnet-free space (not a neat solution) Marcelo Ferreira

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Interface with Magnets, AP and Diagnostics Provide AP vacuum component models for impedance simulation and approval Worked with Magnet Measurement and identified issues with invar chamber supports, and fast corrector response over RF bellows/Al chambers – separate and relocate SC & FC Worked closely with AP on lattice improvement - 3 rd family sextupoles, locations of 3PW, moving of sextupoles, etc RF shielding to shift the resonance frequencies of multipole chambers to > 550 MHz Interference from invar stands Separate SC & FC Om Singh Animesh Jain

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Resonant Frequencies in Multipole Chamber 400MHz1400MHz  Resonant frequencies measured in a 3.4m multipole chamber.  Agreed well with calculated H 101 modes in a rigid waveguide.  Can be shifted by altering the chamber cross sections Electric field To shift the frequencies to > 550 MHz : - increase the slot height to > 15 mm - No - chamber width to < 80mm - No - ante-chamber height to  20 mm - No H 101 Mode in a Rigid Waveguide Alexei Blednykh

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Suppression of Rogue Modes Use modified NEG carriers to create shields in the ante-chamber ~ 150 mm from beam center, installed through end flanges ~ 500 mm long and ~ 300 mm spacing to shift F o to > 550 MHz exact lengths and locations to be decided for each chamber type F o ~ 385 MHz due to S4 absorber in extraction channel? Shields to be outside of SR fan or d/s of absorbers To be designed, prototyped and fully tested with NEG activations Alexei Blednykh S4 150 mm

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 inside fingers outside fingers Choice of RF Shielded Bellows inconel springs Be-Cu fingers Inside fingers Outside fingers (APS, LNLS) (PEP II, Soleil, DLS, …) Simple, reliable Lower impedance $$ $$$ NSLS-II approach - outside fingers, few & wider fingers Solid sleeve Lewis Doom Marcelo Ferreira NSLS-II RF Bellows Requirements: Max mis-alignment: ± 2 mm Max comp/extension: -15/+10 mm Max angle deviation: ±15 mrad Low impedance and low loss Consulted with many experts in other light sources

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 4 Inconel outer springs (Ag plated ) Prototype Bellows Design Hydro formed bellows welded to flanges with cooling channels 4 stainless inner support (Rh plated) 6 GlipCop fingers (0.9 mm thick Ag plated ) 2 stainless clamping plate w/ groove for contact springs Lewis Doom Marcelo Ferreira

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Simulation w/ and w/o offsets At nominal position K loss ≈ 2.0 x10 -2 V/pC With ± 2 mm offset K loss ≈ 3.7 x10 -2 V/pC Simulations of narrow finger bellows: Inside fingers : K loss ≈ 1.9 x10 -2 V/pC ± 2 mm offset ≈ 21.4 x10 -2 V/pC Outside fingers : K loss ≈2.1 x10 -2 V/pC ± 2 mm offset ≈ 8.7 x10 -2 V/pC With ± 2 mm offset K loss ≈ 10 x10 -2 V/pC 6 ” bellows 5 ” bellows Thermal analysis with possible heat loads Detailed production drawings and prototyping Test for ease of assembly, mechanical stability with thermal cycling, etc. Alexei Blednykh

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 TE mode interference to BPM –Extensive studies by AP and Diag groups using chamber extrusions –Modify NEG carriers to shift the frequency to > 550 MHz Clearance between magnets and vacuum chambers –Increased from 1.5 mm to 2 mm at sextupole poles –No foil heaters and insulation – cal rod heater in cooling channel –To be tested with magnets RF shielded bellows design and RF fingers –Consulted with colleagues from other light sources –Preliminary design completed, being detailed and prototyped EPU gap (~ 8 mm) and maximum K values –EDM the top and bottom walls of extraction gap in the S3 dipole (& S2 multipole) chambers to accommodate vertical photon fans ASAC Recommendations – July 08

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Insitu bakeout and temperature uniformity - improved (ΔT < 5 o C) with cal rod heater Extrusion tolerance and stress relief – straightened by machining vendor, < 1 mm relaxation after thermal cycling of bended extrusion NEG supports and protection – will be fully tested and with ground fault protected PS Effect of the vacuum components to magnets – ion pumps ok, invar supports not ok Asymmetric load on chambers due to thermal and mechanical force – analysis continues BPM buttons by welding – long development effort, can’t meet our current schedule 10,000 l/s pumping required at canted DW absorbers – pressure decreases with conditioning, only 1-2 locations Fast valve, Be window & RGA at FE – FV and RGA in the budget, Be windows to be reviewed together with BL Vacuum, FE & Support Review Recommendations – Aug 08

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 BPM position stability after repeated bakeouts –To be tested using the prototype chambers Possible electron cloud –Use CLOUDLAND by Lanfa Wang (SLAC) and NSLS-II staff with worst case parameters –Ex & Ey mainly by electrons from reflected photons –No multipacting, no instability, no emittance blowup –H tune shift < , V tune shift < Fast ion instability –High pressure d/s of canted DW, small impact only be ≤ 2 locations –Need to simulate with beam fill patterns for ion clearing Construction Readiness Review Recommendations – Sept 08 Lanfa Wang

BROOKHAVEN SCIENCE ASSOCIATES SR Chambers & RF Bellows ASAC Review, 3/26-27/ of 21 Summary Cell vacuum chamber detail drawings continue – minor adjustment possible Test extrusion of ‘new’ multipole cross sections continues Machining and weld development of prototype chambers are underway NEG strip supports developed and tested Chamber bakeouts with cal rod heaters being tested RF shielded bellows concept done, to be detailed, prototyped and tested Work with AP & Diag. on shifting resonance frequencies using NEG carriers Production of dipole chambers starts this summer, multipole by Dec Next - Design and prototyping of absorbers and stainless chambers