ANL, Lemont, Illinois, USA
The Advanced Photon Source Upgrade project is progressing from its final design phase into production for the future 6 GeV, 200 mA upgrade of the existing APS. The storage ring arc vacuum system will include over 2500 custom vacuum chambers ranging from 70 mm to 2.5 meters in length and typically feature a narrow 22 mm inner diameter aperture. The scope of NEG coatings was increased to 40% of the length along the e-beam path to ensure efficient conditioning and low pressure requirements can be met. The final design phase required advancing previous work to a procurement-ready level and to address local and system level challenges. Local challenges include designing thin-walled vacuum chambers with carefully controlled lengths and outer profiles and also mitigating significant radiation heat loads absorbed along vacuum chamber walls. System level challenges include planning for the complex machine assembly, networking components to utilities, managing the quality of upcoming procurements. This presentation will highlight the major design challenges and solutions for the storage ring vacuum system and also plans for production and installation.
ANL, Lemont, Illinois, USA
The APS-Upgrade (APS-U) storage ring features a diverse group of vacuum chambers including seven distinctive, non-evaporable getter (NEG)-coated copper vacuum chambers per each of the 40 sectors. These chambers feature a 22-millimeter diameter aperture along the electron-beam path, with two vacuum chambers permitting photon extraction through a keyhole-shaped extension to this aperture. The chambers range from 0.3-meters to 1.7-meters in length and fit within the narrow envelope of quadrupole and sextupole magnets. Six of the seven copper vacuum chambers intercept significant heat loads from synchrotron radiation; five of these designs are fabricated entirely from OFS copper extrusions and are equipped with a compact Glidcop® photon absorber. A hybrid vacuum chamber, fabricated from OFS copper extrusion and a copper chromium zirconium (CuCrZr) keyhole transition, also intercepts synchrotron radiation. The seventh vacuum chamber design features a keyhole aperture across its length and is entirely fabricated from CuCrZr. This paper details the careful balance of vacuum chamber functionality, manufacturability, and the overall design process followed to achieve the final designs.
ANL, Lemont, Illinois, USA
The APS-Upgrade storage ring features a diverse group of vacuum chambers which includes eight NEG (non-evaporable getter) coated aluminum chambers and two copper coated stainless steel keyhole-shaped chambers per sector (40 total). Each chamber contains a 22 mm diameter electron beam aperture; the keyhole chambers also include a photon extraction antechamber. The chambers vary in length of approximately 289 ’ 792 mm and fit within the narrow envelope of quadrupole and sextupole magnets. Each design is a balance of functionality, manufacturability, and installation space. An innovative CAD skeleton model system and ray tracing layout accurately determined synchrotron radiation heat loads on built-in photon absorbers and the internal envelope of the keyhole antechamber. Chamber designs were optimized using thermal-structural FEA for operating and bakeout conditions. The group of chambers require complex manufacturing processes including EDM, explosion-bonded metals, furnace brazing, and welding with minimal space. This paper describes the design process and manufacturing plan for these vacuum chambers including details about FEA, fabrication plans, and cooling/bakeout strategies.