ANL, Argonne, Illinois, USA
A MatLab program has been created to investigate off-orbit ray tracing possibilities for the APS-Upgrade stor-age ring vacuum system design. The goals for the pro-gram include calculating worst case thermal loading conditions and finding minimum shielding heights for photon absorbers. The program computes the deviation possibilities of synchrotron radiation rays emitted along bending magnet paths using discretized local phase space ellipses. The sizes of the ellipses are computed based on multi-bend achromat (MBA) lattice parameters and the limiting aperture size within the future storage ring vacuum system. For absorber height calculations, rays are projected from each point in the discretized ellipse to the locations of downstream absorbers. The absorber heights are mini-mized while protecting downstream components from all possible rays. For heat loads, rays are projected until they hit a vacuum chamber wall. The area and linear power densities are calculated based on a ray's distance trav-elled and striking incidence angle. A set of worse case local heat loads is collected revealing a maximum condi-tion that each vacuum component must be designed to withstand.
ANL, Argonne, Illinois, USA
IIT, Chicago, Illinois, USA
A number of research and development activities are underway at Argonne National Laboratory to build confidence in the designs for the storage ring vacuum system required for the Advanced Photon Source Upgrade project (APS-U) [1]. The predominant technical risks are: excessive residual gas pressures during operation, insufficient beam position monitor stability, excessive beam impedance, excessive heating by induced electrical surface currents, and insufficient operational reliability. Present efforts to mitigate these risks include: building and evaluating mock-up assemblies, performing mechanical testing of chamber weld joints, developing computational tools, investigating design alternatives, and performing electrical bench measurements. Status of these activities and some of what has been learned to date will be shared.
*B. Stillwell et al., Conceptual Design of a Storage Ring Vacuum System Compatible with Implementation of a Seven Bend Achromat Lattice at the APS, in Proc. IPAC'14, Dresden, Germany, 2409-2411.