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

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 therefore requires studying 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 modified stochastic IBS kick is introduced, with friction and diffusion coefficients derived in two forms: an efficient Nagaitsev formulation based on complete elliptic integrals of the second kind, and a complete Bjorken-Mtingwa formulation. This IBS kick is implemented in PyORBIT and extensively benchmarked against analytical models. Results of combined space charge and intrabeam scattering simulations for the SPS and LEIR are presented and compared with observations from beam measurements.