Simulation tools for high intensity rings

Several codes have been developed specifically to simulate beam dynamics in high intensity rings. These codes contain detailed algorithms for modeling the relevant physics in the beam, from single particle transport to important collective effects, including space charge and impedances. Among the various codes, a number of different methods have been adopted for the treatment of space charge. The codes have been applied to a variety of problems in existing machines, as well as for the study, design, and optimization of future machines. A review of existing ring simulation codes is presented, with specific emphasis on the space charge implementation. A more indepth description of the features and application histories of a few specific codes is given, as well as a summary of code benchmarks with experimental data.

INTRODUCTION

The low loss requirements for future high intensity rings will require detailed knowledge of beam dynamics in the machine. Large scale computational models provide an invaluable tool for simulating the multitude of processes that can contribute to beam loss. In particular, in the regime of high beam intensities and low beam energies, collective effects such as space charge and impedances have a significant effect on the beam behavior. In order to predict beam loss at the levels required by future machines, i.e., tiny fractions of the beam intensity, the simulations must realistically account for the entire transport of the beam in the ring, from mapping through external magnetic fields to modeling of collective effects. Due to the complexity of this task, a computational framework is natural. Simulations of this type are productive in the analysis of instability thresholds, halo development! and emittance dilution in existing machines, and are equivalently useful in the design and optimization of future machines.