Post-processing routines for long-term beam stability in accelerators

Abstract

Accelerator complexes require the collaboration of thousands of scientists and engineers to be able to build wonders like the Large Hadron Collider (LHC) at CERN and study all the information obtained with its operation. One of the key aspects for the operation of accelerators is the study of chargedparticle beam optics and dynamics. For instance, the simulation of single-particle trajectories is used to predict and optimize the long-term stability of particle beams inside an accelerator, which can take several hours or about 400 billion revolutions for the LHC. SixTrack is one of the codes used for simulating single-particle dynamics for the LHC and other accelerators. It has been in development for the past 25 years at CERN together with an ecosystem of pre- and post-processing tools (SixDesk) to prepare, launch and process the results of the simulations. This project contributes to SixTrack clarifying the theoretical foundations of the physics behind the post-processing, providing a reference for its code and rewriting part of SixDesk's post-processing routines with modern libraries and re-optimized algorithms together with a critical analysis of the decisions taken in the design process. The results consist in an improvement in term of analysis speed, a simpli cation of the code structure, a thorough documentation of the Fortran post-processing subroutines, the implementation of new features and an improvement in the exposition of the mathematical and physical methods behind the post-processing routines.