SR Vacuum Systems and Front Ends Design Goals & Vacuum Cell Layout Cell Chambers Cross section updates 3-pole wigglers, IR chambers Ray tracing and with canted damping wigglers Absorbers, space allocation Vacuum pumping and pressure profiles Front Ends Summary and Plan NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE Design Goals Adequate Apertures and Low Impedance BSC aperture - 25mm (V) x 76 mm (H) Chamber cross section and straightness/flatness to < 1 mm / 5m Smooth cross section changes (10:1 ratio) Surface finish to ~ μm Clearance between chambers and magnet poles ~ 2mm Low Pressure of < 1 nTorr (> 50% H2), Շ (beam-gas) > 40 hr Low outgassing and desorption after in-situ bake and beam conditioning Intercept photons at discrete absorbers away from the source High effective pumping speed (IP+TSP) at absorber locations 15 IP+TSP per superperiod Distributed NEG strips in ante-chambers for active gases NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE Vacuum Cell Layout Absorber locations 30 vacuum cells of ~ 19m each straights: 8.6m x15 + 6.6m x 15 Isolatable with 60 gate valves IP+TSP locations DW Front End 3PW Front End Cell chamber material: extruded Al 6063-T5 Based on extensive experience at NSLS and APS Developing fabrication procedures with help from APS 50 + 5 + 5 bending chambers - 6o, ~ 3m long (3+ types, 3 lengths) 90 multipole chambers of 3 lengths, 4m, 5m & 3.7m ~ 40 day-one straight section chambers of various lengths extruded Al with similar cross sections as multipole chambers NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

Bending Chamber Cross Section Changes since last review Thicker wall at gap and at NEG slots Relocated cooling channels Bending chamber, ~ 3m long BSC: 25 x 76 mm2 Extruded cross sections SM=45 MPa 3mm wall SY = 145 MPa DY=0.35mm x 2 After machining NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE Multipole Chamber Cross Sections w/ thicker wall BSC: 25 x 76 mm2 Multipole chamber extruded cross section 3.1mm 3-D FEA at the sextupole SM = 94 MPa @ quadrupole SY = 145 MPa 2.9mm DY = 0.33mm x 2 @ sextupole NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

Detailing chamber cross sections for prototype extrusion Detail dimensions w/ tolerances Details on BPM machining, mounting and supports NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE 3-Pole Wiggler and IR Chambers at BM2 3 Pole Wigglers: 32/35mm gap x 20cm at u/s BM2 ~ 2.5 mm wall at center pole Ray tracing at absorber locations BM1 fan 3PW fan ±1 mrad BM2 BM2 fan Crotch absorber d/s of 3-pole wiggler IR Vacuum chambers: 5 x 90mm in 90mm dipoles + 5 x 35mm in regular dipoles Impact to vacuum: outgassing, HOM heating, pumping, etc. Conceptual design of IR chamber in 90mm dipole gap NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE Damping wiggler absorber and crotch absorber at BM1 BM1 Wiggler Absorber DW power 65 kW with ± 2.3 mrad fan, canted ± 1 mrad Absorber: 4.5 kW @ 0.5 mrad x 2; 11 kw @ 1 mrad x 2 Need to clip 1 mrad x 2: to shadow the FE beam pipes Crotch Absorber Canted Damping Wiggler Fans NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE Ray Tracing and Absorbers Crotch absorbers: 2 per cell for BM radiation Stick absorbers (or flange absorber): 4 per cell for BM radiation Wiggler absorbers: for damping wigglers No ring absorbers needed for undulator (and 3 pole wiggler) fans FM to clip DW fan at FE DW fan after 1mrad x 2 by wiggler absorber Stick absorber at 23mm to trim u/s BM1 fan and protect d/s flanges Flange absorber or stick absorber at center of straight to trim u/s BM2 fan and protect d/s bellows and gate valve NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE SR Absorbers – Thermal Analyses Stick Absorber Flange Absorber Crotch Absorber Wiggler Absorber The crotch absorber intercepts 814 W at a normal peak power density of 0.25kW/mm2. A maximum temperature of 105 ºC is calculated. The intercepted power by the wiggler absorber is 11 kW (at 1 mrad x 2) out of 65 kW. This results in a maximum temperature of 427 ºC . The actual temperature is 15 to 20% lower because of scattering. A fatigue life of > 10,000 cycles is expected. Chamber heating? NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

Available space for ID at straight sections = Lattice length – 1.5m Girder stability? End box/transition, BPMs, bellows, gate valve, etc. Space for pumps at girder #3 BPM End box GV DW / EPU UBPM w/ isolated stand? Bellows/ fast correctors NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

UHV Pumping and Pressure Profiles Pavg < 1 nTorr In-situ baking of entire cells at 120 C x 40 hrs To reduce thermal outgassing to < 1x10-12 Torr.l/s/cm2 Whole ring thermal gas load of < 1x10-5 Torr.l/s Pressure will be dominated by photon stimulated desorption (PSD) # photons from 60 BM ~ 1x10+21/s ≈ 7x10-5 Torr.l/s (Assuming η (PSD) = 2x10-6 mol/hv for Cu after ∫hv > 1024/m ) # photons from one 7m DW ~ 6x10+20/s with 15% intercepted by the ring absorber ➱ 7x10-6 Torr.l/s (each DW) NEG strips ~ 1,400 m @ > 100 l/s/m for active gases Reside in ante-chambers as in APS Pump thru the photon slots ( C = ~ 200 l/s/m) Ion pumps and TSP of ~ 500 l/s at absorbers 15 IP/TSP per supercell + 4 at four front ends on day one NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE Pressure Profiles with and w/o Damping Wiggler Radiation By E. Hu & F. Makahleh To be updated Pavg ~ 0.3 nTorr w/ DW Pavg ~ 0.27 nTorr w/o DW Absorber IP/TSP NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

SR Front Ends – Design Concept Pressure of a few nTorr to protect the SR UHV Bakeable to 200 C (all metal, UHV material, etc) IP/TSP combination at high heat load components Day one FE: One photon shutter (PS) for BM radiation FE with insertion devices: One fixed mask (FAPM); two safety shutters (SS) one photon shutter (PS); two X-ray BPMs Typical APS front end NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE Typical layout of hard/soft x-ray beam line front end. Need thermal analysis of all high heat load components for each FE SS x 2 FM: fixed mask; CO: collimator; PS: photon shutter; BDA: beam defining aperture; SS: safety shutter FV GV BPM PS GV BPM CO FM IP/TSP IP/TSP IP/TSP GV: gate valve; FV: fast valve; IP/TSP: ion & titanium sublimation pumps Collimator Photon shutter Safety shutters APS fixed mask design X-BPM NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE

H-C. Hseuh,…, SR Vacuum Systems & FE Summary and Work Plan for 2007 Cell chamber layout with updated lattice – continuing effort Good progress in chamber detail and cross sections with ray tracing Ensure adequate locations and space for absorbers and pumps Extrusion development Detail cell chamber cross sections for prototype extrusion this year Interface with two potential vendors (Taber, Tailien) 4 APS cell chambers and 3 bellows for R&D and evaluation NEG support and assembly R&D, mechanical and fast corrector test 2007+ Plan Continue detail design of chambers, absorbers and FE components collaboration with APS on extrusion details Hire ME, MD and VT, set up vacuum lab MOUs with APS and TLS with access to APS drawings, and TLS Al cleaning development Prototype extrusion of both cross sections with two vendors NSLS-II ASAC Review, 4/23-24/07 H-C. Hseuh,…, SR Vacuum Systems & FE