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Pieloni, T.

Paper Title Page
TUPAS094 Transverse Beam Transfer Functions of Colliding Beams in RHIC 1856
  • W. Fischer, M. Blaskiewicz, R. Calaga, P. Cameron, Y. Luo
    BNL, Upton, Long Island, New York
  • T. Pieloni
    CERN, Geneva
  Funding: Work supported by U. S. DOE under contract No DE-AC02-98CH1-886.

We use transverse beam transfer functions to measure tune distributions of colliding beams in RHIC. The tune has a distribution due to the beam-beam interaction, nonlinear magnetic fields – particularly in the interaction region magnets, and non-zero chromaticity in conjunction with momentum spread. The measured tune distributions are compared with calculations.

THPAN007 Parallel Beam-Beam Simulation Incorporating Multiple Bunches and Multiple Interaction Regions 3235
  • F. W. Jones
    TRIUMF, Vancouver
  • W. Herr
    CERN, Geneva
  • T. Pieloni
    EPFL, Lausanne
  The simulation code COMBI has been developed to enable the study of beam-beam effects in the full collision scenario of the LHC, with multiple bunches interacting at multiple head-on and long-range collision points. The code is structured in a general way, allowing any number of bunches and interaction points (IP's) and procedural options for collisions, beam transport, and output of statistics and coherent mode data. The scale of this problem escalates into the parallel computing arena, and herein we will describe the construction of an MPI-based version of COMBI able to utilize arbitrary numbers of processors to support efficient calculation of multi-bunch multi-IP interactions and transport. After an overview of the basic methods and numerical components of the code, the computational framework will be described in detail and the parallel efficiency and scalability of the code will be evaluated.