Interplay of space charge and intrabeam scattering in the LHC ion injector chain

TL;DR

This paper investigates how space charge and intrabeam scattering interact in CERN's ion injectors, using advanced simulations to optimize beam quality and compare with real measurements.

Contribution

It introduces a modified kinetic theory approach for IBS effects using elliptic integrals, implemented in PyORBIT for faster simulations.

Findings

Successful benchmarking against analytical models

Simulations align with beam measurements in SPS and LEIR

Enhanced understanding of space charge and IBS interplay

Abstract

The ion injectors of the CERN accelerator chain, in particular the Super Proton Synchrotron (SPS) and the Low Energy Ion Ring (LEIR), operate in a strong space charge~(SC) and intrabeam scattering (IBS) regime, which can degrade beam quality. Optimizing the ion beam performance requires thus to study the interplay of these two effects in tracking simulations by incorporating both SC and IBS effects interleaved with lattice nonlinearities. In this respect, the kinetic theory approach of treating IBS effects has been deployed. A new, modified approach has been introduced using the formalism of the Bjorken and Mtingwa model and the complete elliptic integrals of the second kind for faster numerical evaluation. This IBS kick is implemented in PyORBIT and extensive benchmarking cases against analytical models are shown. Results of combined space charge and intrabeam scattering simulations for the SPS and LEIR are presented and compared with observations from beam measurements.