• J.A. Holmes, S.M. Cousineau, V.V. Danilov
  ORNL, Oak Ridge, Tennessee
• Z. Liu
  IUCF, Bloomington, Indiana

As SNS continues to ramp toward full intensity, we are acquiring a wealth of experimental data. Much effort is being applied to understand the details of the beam accumulation process under a variety of experimental conditions. An important part of this effort is the computational benchmarking of the experimental observations. In order to obtain quantitative agreement between the calculations and the observations, and hence a full understanding of the machine, a great deal of care must be taken to incorporate all the relevant experimental parameters into the calculation. These vary from case to case, depending upon what is being studied. In some of these cases, the benchmarks have been critical in unearthing flaws in the machine and in guiding their mitigation. In this paper we present the results of benchmarks with a variety of experiments, including coupling in beam distributions at low intensities, space charge effects at higher intensities, and a transverse instability driven by the impedance of the ring extraction kickers.

• A.P. Shishlo, T.V. Gorlov, J.A. Holmes
  ORNL, Oak Ridge, Tennessee

A development of a Python driving shell for the ORBIT simulation code is presented. The original ORBIT code uses the Super Code shell to organize accelerator related simulations. It is outdated, unsupported, and it is an obstacle for the future code development. A necessity of the replacement of the old shell language and consequences are discussed. A set of modules that are currently in the core of the pyORBIT code and extensions are presented. They include particle containers, parsers for MAD and SAD lattice files, a Python wrapper for MPI libraries, space charge calculators, TEAPOT trackers, and a laser stripping extension module.