Author: Mulvany, O.K.
Paper Title Page
MOPC11 Discrete Photon Absorbers for the APS-Upgrade Storage Ring Vacuum System 75
 
  • O.K. Mulvany, B. Billett, B. Brajuskovic, J.A. Carter, A. McElderry, R.R. Swanson
    ANL, Lemont, Illinois, USA
 
  Funding: This work is supported by the U.S. Department of Energy, Office of Science under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source Upgrade storage ring arc vacuum system features a diverse set of photon beam-intercepting components, including five discrete photon absorbers and a series of small-aperture vacuum chambers that shadow downstream components. The discrete photon absorbers, typically fabricated from electron beam-welded GlidCop AL-15, are subject to heat loads ranging from approximately 170 to 3400 watts, with a peak power density up to approximately 610 W/mm2 at normal incidence. Four of the five photon absorber designs are housed in vacuum chambers, including three that are mounted to the antechambers of curved aluminum extrusion-based L-bend vacuum chambers and one that is mounted to a stainless steel vacuum-pumping cross. Furthermore, two of the photon absorbers that are mounted to L-bend vacuum chambers are equipped with position-adjustment mechanisms, which are necessitated by the challenging design and fabrication of the curved vacuum chambers. The fifth photon absorber, unlike the rest, is a brazed design that is integral in sealing the vacuum system and intercepts approximately 170 watts. Each photon absorber design was optimized with thermal-structural finite element analyses while ensuring functional and spatial requirements were met. Some of these requirements include meeting internal high-heat-load component design criteria, respecting challenging component interfaces and alignment requirements, and minimizing impedance effects. Furthermore, photon beam scattering effects called for the use of scattering shields on three designs to minimize potential heating of vacuum chambers. This paper details the careful balance of functionality and manufacturability, and the overall design process followed to achieve the final designs.
 
poster icon Poster MOPC11 [8.305 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-MOPC11  
About • paper received ※ 19 July 2021       paper accepted ※ 13 October 2021       issue date ※ 01 November 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPC14 Vacuum Pumping Crosses and Keyhole Vacuum Chambers for the APS-Upgrade Storage Ring Vacuum System 85
 
  • A. McElderry, B. Billett, J.A. Carter, O.K. Mulvany
    ANL, Lemont, Illinois, USA
 
  Funding: This work is supported by the U.S. Department of Energy, Office of Science under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source Upgrade (APS-U) storage ring arc consists of a diverse system of nar-row-aperture chambers in compact magnet assemblies with gaps often less than 1 mm. The vacuum system contains two stainless steel pumping crosses and two keyhole-shaped vacuum chambers, as well as eight non-evaporative getter (NEG) coated aluminum cham-bers and crosses per sector (40 total sectors). Each chamber contains a 22 mm diameter electron beam aperture and the keyhole components also feature a photon extraction antechamber. Each design balances functionality, manufacturability, and installation needs. The design process was aided by a flexible CAD skeleton model which allowed for easier adjustments. Synchrotron radiation heat loads applied to inline chamber photon absorbers and photon extraction beam envelopes were determined via a 3D ray tracing CAD model. The inline photon absorber and the key-hole shapes were optimized using iterative thermal-structural FEA. Focus was put on mesh quality to mod-el the <0.5 mm tall synchrotron radiation heat load absorbed across the length of the chamber to verify cooling parameters. The design process also required careful routing of the water system and vacuum pumps. The designs incorporate beam physics con-straints of the inline absorbers, cross-housed discrete absorbers, and pumping slots.
 
poster icon Poster MOPC14 [11.188 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-MOPC14  
About • paper received ※ 16 July 2021       paper accepted ※ 13 October 2021       issue date ※ 03 November 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)